OAuth authentication : custom provider

[vd3d]

Currently, Supabase support a set of predefined oauth2 providers, but they are "almost" all the same.
behind, they just use different urls etc.

I'm looking to use OAuth with a set of other providers (not listed) and it will be very useful if we can add a set of new "custom" oauth providers from the user interface. For example, we can only provides the authorization & token urls etc... maybe some additional settings.

BTW, I have see a lot of other requests for integration with others OAuth providers (Steam, wechat, telegram, yahoo, etc etc) , this requests should solve all thoses requests.

It should be very easy to add (because you already have 99% of the codebase).

Thanks