Centralise static OAuth2 properties (auth URL, token URL, scopes,
extra params, token endpoint auth) per provider in a single map.
This removes the need to duplicate these values in deployment
config; only ClientID and ClientSecret remain configurable.
Introduces ApplyProviderDefaults to set redirect URI and provider
defaults onto an OAuth2Connector at wiring time.
Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>
f7085f98be