OAUTH Additional claims

[serg-bs]

Is your feature request related to a problem? Please describe.

We have Identity provider for multiple applications.
We want to have granular access. For that we need additional claims

For example https://www.pgadmin.org/docs/pgadmin4/8.3/oauth2.html
OAUTH2_ADDITIONAL_CLAIMS
Pgadmin example

{
    'OAUTH2_NAME': 'SAP',
    'OAUTH2_DISPLAY_NAME': 'SAP IAS',
    'OAUTH2_CLIENT_ID': '<clientId>',
    'OAUTH2_CLIENT_SECRET': '<clientSecret>',
    'OAUTH2_TOKEN_URL': '<ias base url>oauth2/token',
    'OAUTH2_AUTHORIZATION_URL': '<ias base url>oauth2/authorize',
    'OAUTH2_SERVER_METADATA_URL': '<ias base url>.well-known/openid-configuration',
    'OAUTH2_API_BASE_URL': '<ias base url>',
    'OAUTH2_USERINFO_ENDPOINT': '<ias base url>oauth2/userinfo',
    'OAUTH2_SCOPE': 'openid email profile',
    'OAUTH2_USERNAME_CLAIM': 'email',
    'OAUTH2_ICON': 'fa-sign-in',
    'OAUTH2_BUTTON_COLOR': '#F0AB00'
    'OAUTH2_ADDITIONAL_CLAIMS': {
        'groups': ['pgadmin']
    }
}

Describe the solution you'd like

Introduce additional variables to pass claims