TLSRoute promotion to standard

[mlavacca]

What would you like to be added:

This is an umbrella issue that gathers all the issues that need to be addressed in order to promote TLSRoute to standard.

As an additional and potentially useful resource, the following is the original google docs on the Gateway API TLS use cases: https://docs.google.com/document/d/17sctu2uMJtHmJTGtBi_awGB0YzoCLodtR6rUNmKMCs8/edit#heading=h.cxuq8vo8pcxm

API improvement

Beta Give feedback

1. Support TLS Termination mode for TLSRoutes #2111
   kind/feature needs-triage +2

Documentation

Beta Give feedback

1. GEP: TLSRoute #2643
   kind/gep +1
   
2. TLS support docs inconsistencies #1474
   documentation kind/bug triage/accepted +3
3. Conflicting SNI's between HTTPRoute & TLSRoute #623
   help wanted kind/bug priority/backlog +3

Conformance

Beta Give feedback

1. Conformance Tests: TLSRoute Passthrough #1579
   area/conformance priority/backlog +2
2. conformance: Coverage for request routing to TLSRoute with no valid BackendRefs #2153
   area/conformance priority/backlog triage/accepted +3

[candita]

@mlavacca we probably need to address #2263 as well. I think it was merged in error. cc @robscott @shaneutt @youngnick @kate-osborn