Add an optional annotation for disableSubdomainIsolation config

[vinokurig]

Is your enhancement related to a problem? Please describe

There is an ability to configure OAuth for Github Enterprise server without subdomain isolation added by #21724 :

spec:
  gitServices:
    github:
      - endpoint: 'https://github.com'
        secretName: github-oauth-config
        disableSubdomainIsolation: true

It would be great to have the similar configuration via the oauth secret annotations.

Describe the solution you'd like

Add an optional annotation field to the github oauth secret config e.g.

  annotations:
    che.eclipse.org/oauth-scm-server: github
    che.eclipse.org/scm-server-endpoint: <github_server_url>
    che.eclipse.org/scm-github-disableSubdomainIsolation: <true/false>

Describe alternatives you've considered

No response

Additional context

See #21964

[tolusha]

What about che.eclipse.org/scm-disable-subdomain-isolation

[vinokurig]

What about che.eclipse.org/scm-disable-subdomain-isolation

This is a GitHub server specific property so I think we should keep github in it's name

[tolusha]

Agreed, so che.eclipse.org/scm-github-disable-subdomain-isolation

[tolusha]

@l0rd What do you think?

[l0rd]

That works for me

[l0rd]

@tolusha we should remove endpoint and disableSubdomainIsolation from CheCluster spec.gitServices too.