GEP: GatewayClass status supported features

[LiorLieberman]

What would you like to be added:
Improve UX by enabling them to easily see what features their installed GatewayClass support.

Why this is needed:
With the evolution of the Conformance tests suite and features, we want to;

1. Enable users easily see what features the implementation support
2. Improving UX and potentially provide clear errors when a user is trying to use a feature the installed GWC doesn't support

cc: @shaneutt

[LiorLieberman]

/kind gep

[LiorLieberman]

/remove-help