Add support for listing the available tables

Something like
const { data } = await supabase.from() // Returns ["projects", etc]
Or pehaps via the CLI
supabase gen keys // Add an additional key something like tables to list all the tables

Considered workaround (Suggested by @GaryAustin1 )
SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'; returns all the table names in the public schema.