feat: WebAssembly filter chains

[hishamhm]

This PR introduces the FilterChains entity, a new entity released in Kong Gateway 3.4 (OSS and Enterprise) to manage WebAssembly filters ("filters" are the WebAssembly analog to Lua plugins — we call them filters because it's the already-established terminology used by the proxy-wasm API we implemented, which is also implemented by other WebAssembly-enabled gateways such as Envoy).

---

KAG-4005
KOKO-1274

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 60.73620% with 64 lines in your changes are missing coverage. Please review.

Project coverage is 59.34%. Comparing base (241dbb8) to head (2ee7cad).

Files	Patch %	Lines
kong/filter_chain_service.go	61.97%	27 Missing and 27 partials ⚠️
kong/filter_chain.go	0.00%	6 Missing ⚠️
kong/consumer_group_consumer_service.go	60.00%	3 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #362      +/-   ##
==========================================
+ Coverage   59.32%   59.34%   +0.01%     
==========================================
  Files          69       71       +2     
  Lines        4219     4378     +159     
==========================================
+ Hits         2503     2598      +95     
- Misses       1134     1170      +36     
- Partials      582      610      +28     

Flag	Coverage Δ
2.1	35.60% <0.61%> (-1.32%)	⬇️
2.2	48.21% <1.22%> (-1.80%)	⬇️
2.3	48.85% <1.22%> (-1.82%)	⬇️
2.4	48.90% <1.22%> (-1.82%)	⬇️
2.5	48.90% <1.22%> (-1.82%)	⬇️
2.6	48.90% <1.22%> (-1.82%)	⬇️
2.7	50.61% <4.90%> (-1.82%)	⬇️
2.8	50.61% <4.90%> (-1.82%)	⬇️
3.0	54.56% <4.90%> (-1.97%)	⬇️
3.1	56.21% <4.90%> (-2.03%)	⬇️
3.2	56.25% <4.90%> (-2.03%)	⬇️
3.3	56.25% <4.90%> (-2.03%)	⬇️
3.4	58.65% <60.73%> (+0.04%)	⬆️
community	43.30% <56.44%> (+0.54%)	⬆️
enterprise	57.94% <60.73%> (+0.06%)	⬆️
integration	59.34% <60.73%> (+0.01%)	⬆️

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[hishamhm]

Regarding the failing test: we probably need KONG_WASM=on set on the 3.4/nightly tests for the filter chain operations to work, and probably KONG_WASM_FILTERS_PATH=filters/ as well, containing a dummy filters/example-filter.wasm

[CLAassistant]

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[flrgh]

CI problems...

The nightly tests were using an old tag (master-alpine), so those tests were broken for filter chains. I updated this to master. However, now some other tests are failing now that they are being executed against a real nightly image:

=== RUN   TestFillPluginDefaults/no_config_no_protocols
    plugin_service_test.go:671:   &kong.Plugin{
          	... // 6 identical fields
          	Consumer:      nil,
          	ConsumerGroup: nil,
          	Config: kong.Configuration{
          		"anonymous":        nil,
          		"hide_credentials": bool(false),
        - 		"realm":            string("service"),
          	},
          	Enabled: &true,
          	RunOn:   &"test",
          	... // 3 identical fields
          }

[flrgh]

Lint fixes are in #421

[flrgh]

I had to fix a host of testing problems in order to get CI working against Kong nightly/master, so there are a bunch of additional commits in this PR. I can move them to another PR if desired.

[flrgh]

@hishamhm who is a good person to tag for review on this?

[rainest]

The consumer groups stuff should have probably gone in separately but otherwise the new entity looks fine.

[pmalek]

#362 (comment) is being addressed in #432