Support prefix-list BGP policies

[wenovus]

• Convert OC policies to GoBGP policies in configuration in the reconciler.
• Add BGP policy test spec. This is adapted from an existing one.
• Add prefix-list policy test.

[DanG100]

is reason with a proto and not just a struct?

[wenovus]

So there is another BGP policy testing framework that the user of this is looking at that currently uses this as the test interface. I'm simply using it here for uniformity and so I don't need to re-invent this. If there is no need for using a proto we can later change it, but it doesn't seem to have any harm.

[github-actions]

Pull Request Test Coverage Report for Build 5050896170

• 193 of 210 (91.9%) changed or added relevant lines in 5 files are covered.
• 68 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.09%) to 2.483%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
bgp/gobgp.go	161	166	96.99%
gnmi/gnmi.go	4	9	44.44%
bgp/ocgobgp.go	21	28	75.0%

Files with Coverage Reduction	New Missed Lines	%
dataplane/internal/engine/engine.go	29	0%
gnmi/oc/networkinstance/networkinstance-0.go	39	0.27%

Totals
Change from base Build 5048647217:	0.09%
Covered Lines:	13112
Relevant Lines:	528058

---

💛 - Coveralls

[wenovus]

There are some strange non-deterministic errors appearing:

Locally running make test-race, this happened once:

--- FAIL: TestBGPGUEPolicy (20.45s)                                                                                                                                                                                                                                                                   
    --- FAIL: TestBGPGUEPolicy/v6 (10.20s)                                                                                                                                                                                                                                                            
        --- FAIL: TestBGPGUEPolicy/v6/Add_Policy (0.00s)                                                                                                                                                                                                                                              
            server_test.go:1950: Got duplicate route key:                                                                                          
                First: &{RouteKey:{Prefix:2001::1400:0:0:0/72 NIName:DEFAULT} Nexthops:map[{NextHopSummary:{Weight:0 Address:2001::c0a8:12a:0:0 NetworkInstance:DEFAULT} Port:{Name:eth0 Index:0 Subinterface:0} GUEHeaders:{GUEPolicy:{dstPortv4:0 dstPortv6:8 srcIP4:[0 0 0 0] srcIP6:[32 1 0 0 0 0 
0 0 42 42 42 42 0 0 0 0]} dstIP4:[0 0 0 0] dstIP6:[32 1 0 0 0 0 0 0 192 168 1 42 0 0 0 0] isV6:true}}:true]}                                                                                                                                                                                          
                Duplicate: &{RouteKey:{Prefix:2001::1400:0:0:0/72 NIName:DEFAULT} Nexthops:map[{NextHopSummary:{Weight:0 Address:2001::c0a8:12a:0:0 NetworkInstance:DEFAULT} Port:{Name:eth0 Index:0 Subinterface:0} GUEHeaders:{GUEPolicy:{dstPortv4:0 dstPortv6:8 srcIP4:[0 0 0 0] srcIP6:[32 1 0 0 
0 0 0 0 42 42 42 42 0 0 0 0]} dstIP4:[0 0 0 0] dstIP6:[32 1 0 0 0 0 0 0 192 168 1 42 0 0 0 0] isV6:true}}:true]}

With GitHub actions I've commented where bgp/tests/local_tests is failing due to a stale cache update -- I have no idea how that could happen since all gNMI operations for these tests happen sequentially, and tests are also run sequentially since they're in the same package: https://github.com/openconfig/lemming/actions/runs/5050247039/jobs/9060715556

Lastly there was a recursive cmp transformer failure that I also have no idea happened: https://github.com/openconfig/lemming/actions/runs/5050317179/jobs/9060884938

This is just a note for the future if these errors occur to help with debugging.