Moves system-level operations (auth, billing, admin) to use the
/metadata endpoint instead of /graphql.
This cleans up the endpoint separation so /graphql is purely for core
objects (Company, People, etc.) and /metadata handles all system
operations.
Part of prep work for webhook/API key core migration.
This PR:
- creates the query to delete a connection
- creates the hook that triggers the query
- triggers the hook function when clicking on remove + get back to
connection page
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Co-authored-by: Thomas Trompette <thomast@twenty.com>