[gwctl] Expand the output of gwctl describe httproute

[gauravkghildiyal]

What type of PR is this?

/kind feature

What this PR does / why we need it:

This PR builds upon the great work by @tdn21 in https://github.com/kubernetes-sigs/gateway-api/pull/3071. I've rebased, added a new commit adding the requested tests and made some minor changes.

Which issue(s) this PR fixes:

Fixes https://github.com/kubernetes-sigs/gateway-api/issues/3037

Does this PR introduce a user-facing change?:

The output of `gwctl describe httproute <NAME>` now includes more details

/assign @mlavacca /cc @tdn21