AttachedRoutes not necessarily on accepted routes and listeners

[tanujd11]

Description:
With the PR given below, change in Listener or Route status does not impact successful attachment. At the moment we only increment this count when route and listener is accepted.

[optional Relevant Links:]
kubernetes-sigs/gateway-api#2396

[danehans]

/assign

[danehans]

xref kubernetes-sigs/gateway-api#2477 adds a conformance test upstream that exercises the attachedRoutes spec update.

[danehans]

@arkodg this issue is more involved than what I expected. I created the above draft PR that can be used as guidance for a proper PR to fix this issue.