B7.3 Endpoint which redirects to OAuth2 provider

[joshgarde]

Endpoint should utilize the load functionality from B7.1 to generate a redirect to an OAuth2 provider, appending the client id/secret parameters to the URL, to start an authorization code grant.

Eg. http://LETSMESH/authorize/discord -(302)-> https://discord.com/oauth2/authorize?response_type=code&client_id=123456&redirect_uri=http://LETSMESH/...

The endpoint should also handle appending any other necessary information (eg. scope) to the URL for the OAuth2 provider. The redirect_uri is to be set to the endpoint created in B7.3.