Adding some standard OpenID Connect providers (Google, Facebook) (WIP):

* frontend

server/lib/external-auth/oidc.ts

@@ -1,6 +1,7 @@
 import type { RegisterServerOptions } from '@peertube/peertube-types'
 import type { Request, Response, CookieOptions } from 'express'
 import type { ExternalAccountInfos, AcceptableAvatarMimeType } from './types'
+import type { ExternalAuthOIDCType } from '../../../shared/lib/types'
 import { ExternalAuthenticationError } from './error'
 import { getBaseRouterRoute } from '../helpers'
 import { canonicalizePluginUri } from '../uri/canonicalize'
@@ -68,8 +69,6 @@ async function getRandomBytes (size: number): Promise<Buffer> {
   })
 }
 
-type ExternalAuthOIDCType = 'custom' | 'google' | 'facebook'
-
 /**
  * This class handles the external OpenId Connect provider, if defined.
  */