control-plane: change authz grants of unchanged_draft_specs view

[psFried]

Description:

Initially, the unchanged_draft_specs view was written as being owned by the authenticated role in postgres, to ensure that it always used the RLS policies of the caller. But Supabase has revoked the superuser attribute of the postgres role and no longer provides a way to authenticate as a superuser. This means that alter view ... set owner to authenticated no longer works because authenticated does not have the necessary permission to create a view. See this thread for more.

In this case, we're able to work around this by granting select permission to the authenticated role. This works because both draft_specs_ext and live_specs_ext perform their own enforcement of authZ, so it's safe to bypass RLS.

Also changes the name of the migration to fix a conflict.

Workflow steps:

I re-tested authZ of the view by:

• create aliceCo/ tenant and create a hello-world capture
• start editing that capture and hit the re-fresh button
• confirm that there's 2 rows in unchanged_draft_specs
• create bobCo/ tenant and repeat the above steps
• confirm that there's 4 rows in unchanged_draft_specs when querying as superuser, but only 2 rows when using flowctl raw get to query as alice or bob.

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This change is 

[jgraettinger]

LGTM