branch-3.1: [Improve](variant) optimize cast performance when variant only contains null values #57003

[csun5285]

pick from master #57003

[hello-stephen]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[csun5285]

run buildall

[csun5285]

run buildall

[doris-robot]

TPC-H: Total hot run time: 32836 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpch-tools
Tpch sf100 test result on commit f9e85ffb1d48f5b63228096c509d39a0bb4686cd, data reload: false

------ Round 1 ----------------------------------
q1	17625	5457	5514	5457
q2	2035	398	285	285
q3	11841	1282	778	778
q4	10335	879	455	455
q5	9021	2433	2172	2172
q6	194	173	134	134
q7	916	745	621	621
q8	9349	1495	1154	1154
q9	5275	5036	4947	4947
q10	6759	2269	1814	1814
q11	497	279	253	253
q12	332	358	213	213
q13	17763	3613	2979	2979
q14	228	235	212	212
q15	536	478	465	465
q16	425	427	377	377
q17	609	875	359	359
q18	6917	6551	6398	6398
q19	1215	983	555	555
q20	337	354	223	223
q21	3064	2199	2015	2015
q22	1075	993	970	970
Total cold run time: 106348 ms
Total hot run time: 32836 ms

----- Round 2, with runtime_filter_mode=off -----
q1	5579	5535	5566	5535
q2	232	333	235	235
q3	2270	2644	2328	2328
q4	1342	1845	1394	1394
q5	4470	5008	5026	5008
q6	173	165	128	128
q7	2087	1998	1810	1810
q8	2674	2881	2726	2726
q9	7322	7261	7287	7261
q10	3041	3262	2766	2766
q11	589	512	483	483
q12	717	757	646	646
q13	3352	3809	3162	3162
q14	279	290	287	287
q15	525	473	470	470
q16	442	483	420	420
q17	1239	1750	1257	1257
q18	7662	7489	7358	7358
q19	881	1177	1188	1177
q20	2025	2065	1896	1896
q21	5417	4986	4620	4620
q22	1086	1045	1022	1022
Total cold run time: 53404 ms
Total hot run time: 51989 ms

[doris-robot]

TPC-DS: Total hot run time: 192697 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpcds-tools
TPC-DS sf100 test result on commit f9e85ffb1d48f5b63228096c509d39a0bb4686cd, data reload: false

query1	944	416	406	406
query2	6440	1975	1938	1938
query3	9077	212	204	204
query4	34274	24260	23616	23616
query5	3831	621	443	443
query6	280	219	176	176
query7	4205	489	324	324
query8	294	246	232	232
query9	9628	2614	2615	2614
query10	497	350	266	266
query11	18519	15723	15237	15237
query12	152	113	111	111
query13	1557	534	407	407
query14	9390	7796	6698	6698
query15	234	191	178	178
query16	8017	636	550	550
query17	1556	765	600	600
query18	2231	429	337	337
query19	225	203	179	179
query20	134	128	115	115
query21	219	132	113	113
query22	4710	4628	4513	4513
query23	35414	34367	34022	34022
query24	7379	2724	2703	2703
query25	512	493	403	403
query26	1182	290	172	172
query27	2082	492	369	369
query28	5163	2220	2179	2179
query29	754	592	440	440
query30	244	195	162	162
query31	1029	946	832	832
query32	88	63	62	62
query33	505	371	313	313
query34	746	842	530	530
query35	810	846	740	740
query36	1001	1063	966	966
query37	104	97	73	73
query38	4153	4002	3975	3975
query39	1530	1515	1509	1509
query40	221	134	115	115
query41	50	76	49	49
query42	126	105	103	103
query43	525	516	479	479
query44	1345	819	819	819
query45	183	179	168	168
query46	893	1073	679	679
query47	2033	2034	1962	1962
query48	424	445	352	352
query49	778	505	406	406
query50	681	712	436	436
query51	7363	7344	7107	7107
query52	106	103	97	97
query53	236	271	189	189
query54	557	556	472	472
query55	82	82	85	82
query56	266	286	265	265
query57	1281	1290	1251	1251
query58	243	222	240	222
query59	3027	3235	3047	3047
query60	304	293	267	267
query61	125	115	123	115
query62	828	761	707	707
query63	244	198	200	198
query64	4561	1088	743	743
query65	3433	3312	3353	3312
query66	1049	439	331	331
query67	16403	15821	15563	15563
query68	5078	829	543	543
query69	490	340	283	283
query70	1199	1118	1141	1118
query71	373	304	270	270
query72	5855	3859	3837	3837
query73	629	757	362	362
query74	10079	9135	8961	8961
query75	3215	3159	2727	2727
query76	3034	1173	792	792
query77	483	364	281	281
query78	10409	10483	9717	9717
query79	3657	910	595	595
query80	705	525	446	446
query81	496	254	224	224
query82	564	119	87	87
query83	164	164	147	147
query84	246	100	82	82
query85	794	385	304	304
query86	385	301	292	292
query87	4314	4309	4241	4241
query88	5219	2423	2422	2422
query89	415	334	294	294
query90	1826	192	189	189
query91	136	143	115	115
query92	69	61	54	54
query93	2600	875	533	533
query94	693	401	321	321
query95	349	280	290	280
query96	490	614	286	286
query97	3155	3266	3124	3124
query98	221	211	195	195
query99	1433	1417	1332	1332
Total cold run time: 295252 ms
Total hot run time: 192697 ms

[doris-robot]

ClickBench: Total hot run time: 29.32 s

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/clickbench-tools
ClickBench test result on commit f9e85ffb1d48f5b63228096c509d39a0bb4686cd, data reload: false

query1	0.03	0.04	0.03
query2	0.07	0.02	0.03
query3	0.24	0.06	0.06
query4	1.62	0.11	0.10
query5	0.52	0.50	0.53
query6	1.13	0.75	0.73
query7	0.03	0.02	0.01
query8	0.05	0.04	0.03
query9	0.60	0.50	0.49
query10	0.55	0.55	0.56
query11	0.15	0.10	0.10
query12	0.13	0.11	0.11
query13	0.62	0.61	0.60
query14	0.80	0.79	0.80
query15	0.84	0.83	0.83
query16	0.38	0.38	0.37
query17	1.04	1.08	1.04
query18	0.24	0.22	0.22
query19	1.91	1.86	1.84
query20	0.02	0.01	0.02
query21	15.37	0.97	0.58
query22	0.74	0.75	0.61
query23	15.20	1.44	0.62
query24	3.25	1.51	1.22
query25	0.25	0.12	0.13
query26	0.25	0.15	0.15
query27	0.04	0.05	0.05
query28	14.17	1.00	0.44
query29	12.57	3.95	3.31
query30	0.25	0.08	0.06
query31	2.81	0.60	0.38
query32	3.22	0.54	0.46
query33	2.98	3.06	3.07
query34	16.71	5.20	4.52
query35	4.59	4.53	4.59
query36	0.66	0.49	0.47
query37	0.08	0.06	0.06
query38	0.04	0.04	0.03
query39	0.04	0.02	0.02
query40	0.17	0.14	0.12
query41	0.08	0.03	0.03
query42	0.03	0.02	0.02
query43	0.04	0.04	0.03
Total cold run time: 104.51 s
Total hot run time: 29.32 s