Prepare release. Fix introduced build step and exposed supabase types

[sduduzog]

• Added workflow to publish package to beta tag, only when it's marked as a prerelease
• Exposed supabase types, this helps avoid installing @supabase/supabase-js for common types
• Fix issue with supabase options passed down the plugin. Closes vue+supabase supabaseOptions is not being respected by nuxt+supabase #16

Note: This only touches up on the previously merged repository ensuring that everything still works with the nuxt bridge. Some shiny new parts introduced by it i.e. ssr support and firebase like vuex hooks will be prioritised after.

[scottrobertson]

LGTM