feat: Allow to accept a shared drive with a SSO (#4586)

Adds support for accepting shared drives using Single Sign-On (OIDC)
authentication, with dynamic company branding for private OIDC
providers. Users can now authenticate via either their organization's
OIDC provider or the public Twake OIDC service when accepting a sharing
invitation.

Author: shepilov

.gitignore

@@ -28,3 +28,5 @@ tmp
 /debian/cozy/
 /debian/cozy-stack/
 /debian/tmp/
+/.gocache
+/.idea