Set Accepted condition and bump observed gen for all GatewayClasses with our controller name

[kate-osborn]

The GatewayClassObservedGenerationBump conformance test expects any GatewayClass with the NKG controller name to have the Accepted condition set and the observed generation bumped on update.

Acceptance Criteria:

• All GatewayClasses that have our controller name, must have the Accepted condition on it. Can be false if the GatewayClass name does not match the one provided via cli arg.
• All GatewayClasses that have our controller name, must have the observed generation of all its Status. Conditions bumped after a spec update.
• Make sure the GatewayClassObservedGenerationBump passes.