refactor: Improve linting and formatting pipeline

[Ahzyuan]

1. Updated the order and the commands of linting and formatting
2. Refactor the source codes and the test codes to meet the latest linting and formatting requirements.

[github-actions]

Coverage Details on macos under Python 3.8

File	Stmts	Miss	Cover	Missing
_stat_numeric.py	113	0	100%
config.py	280	10	96%	330, 367, 509, 515, 579–584
core.py	370	13	96%	417–418, 423, 460–461, 522, 664, 729, 792, 856, 1819, 1825, 1830
display.py	436	6	98%	83, 437–438, 440, 799, 901
engine.py	106	0	100%
statistic.py	443	15	96%	54, 60, 66, 72, 77, 207, 792, 850–855, 868–869
unit.py	41	0	100%
utils.py	127	1	99%	71
TOTAL	1916	45	97%

Summary (on macos under Python 3.8)

Tests	Skipped	Failures	Errors	Time
806	2 💤	0 ❌	0 🔥	9.287s ⏱️

[github-actions]

Coverage Details on ubuntu under Python 3.8

File	Stmts	Miss	Cover	Missing
_stat_numeric.py	113	0	100%
config.py	280	10	96%	330, 367, 509, 515, 579–584
core.py	370	13	96%	417–418, 423, 460–461, 522, 664, 729, 792, 856, 1819, 1825, 1830
display.py	436	6	98%	83, 437–438, 440, 799, 901
engine.py	106	0	100%
statistic.py	443	15	96%	54, 60, 66, 72, 77, 207, 792, 850–855, 868–869
unit.py	41	0	100%
utils.py	127	1	99%	71
TOTAL	1916	45	97%

Summary (on ubuntu under Python 3.8)

Tests	Skipped	Failures	Errors	Time
806	2 💤	0 ❌	0 🔥	12.217s ⏱️

[github-actions]

Coverage Details on windows under Python 3.8

File	Stmts	Miss	Cover	Missing
_stat_numeric.py	113	0	100%
config.py	280	10	96%	330, 367, 509, 515, 579–584
core.py	370	13	96%	417–418, 423, 460–461, 522, 664, 729, 792, 856, 1819, 1825, 1830
display.py	436	6	98%	83, 437–438, 440, 799, 901
engine.py	106	0	100%
statistic.py	443	15	96%	54, 60, 66, 72, 77, 207, 792, 850–855, 868–869
unit.py	41	0	100%
utils.py	127	1	99%	71
TOTAL	1916	45	97%

Summary (on windows under Python 3.8)

Tests	Skipped	Failures	Errors	Time
806	2 💤	0 ❌	0 🔥	12.773s ⏱️