MeshHTTPRoute basic api implementation

[michaelbeaumont]

Description

Implement #4743

• Implement plugin ordering
• "Feature flag" for new routes -> if new route policies exist, only use new route policies
• Implement MeshHTTPRoute targetRef-based & matches-based merging
  • this requires significant refactoring because it's assumed everywhere that the to struct has a Default field
• Generate outbound listeners from Dataplane spec
  • handles default route/TcpProxy
• Generate clusters from new routes
  • 1st iteration - same cluster generation
• Generate routes on outbound listeners from new routes
  • Including ExternalServices
  • kuma.io/service for Dataplanes has priority over ExternalServices
    • document and warn about this
  • targetRef.kind: ExternalService as backendRef?
• Generate endpoints
• ZoneIngress support for new routes
  • needs only backendRefs for destinations
• No MeshGateway support

[michaelbeaumont]

I think this can be parallelized:

1. refactor the policy code to support a plugin with a policy that doesn't have the expected To structure
2. implement the plugin given a merged "rules" view of all routes

[lahabana]

FYI this issue doesn't cover Mirror which is covered by: #724

[michaelbeaumont]

After #5530:

• test resource builder
• unify gateway and DP cluster naming #5793
• https://github.com/kumahq/kuma/pull/5530/files#r1064599622
• inspect API

Schema

• MeshHTTPRoute header matching #5794
• chore(MeshHTTPRoute): support url rewriting #5776
• MeshHTTPRoute redirect: path modifier #5795
• MeshHttpRoute implement mirror filter #5796
• MeshHTTPRoute implement direct response #5798

Validation

• MeshHTTPRoute check and add extra validation #5799

[lahabana]

As other issues are tracked somewhere else going to close this