Report the number of Route and Gateway ClientSettingPolicies

[mpstefan]

As a maintainer of NGF
I want to collect the number of ClientSettings, Observability, and NginxProxy Policies used in NGF for each context they are used in
So that I can understand how popular ClientSettings policies are and at what context they are most often used at
So that I can better prioritize features for NGF.

Acceptance

• The number of ClientSettings policies are reported as two separate values, one for Gateway level attachments and the other for Route level attachment.
• The number of total Observability policies are reported.
• The number of NginxProxy policies are reported.

[kate-osborn]

@mpstefan should NginxProxy be included in this story? It's not a policy, it's a ParametersRef and there can only be one NginxProxy that is accepted by our controller.