Support API key generation

Feature request Please support generating user-tied API keys via supabase-js/GoTrue Is your feature request related to a problem? Please describe. I'm developing an open API. Users can sign into a web portal and generate API tokens to be used when communicating with the API. Users can generate multiple tokens, e.g. if they want to use different keys for Android and iOS client applications and track their usage separately. Currently, I can find no good way of generating such tokens/API keys without exposing secrets or breaking RLS. Describe the solution you'd like It should be possible to create an "authorized token"/"api key"/other static string for signed in users. Such tokens could be stored in an access_tokens(user_id uuid, access_token varchar, created_at timezonetz) table in the auth schema. This token should then be possible to supply in the request header instead of a jwt when accessing supabase. Queries using this token should be…