[BUDI-6570] Custom Domain (Cloud Only)

[budibot]

When I'm using my budibase cloud tenant I want to be able to access it from a custom domain so that I have more control.

COS

• Provide UI in portal to wire up budibase to a custom domain that will redirect requests to the custom domain (eg. `https://internal-tools.acme.com`) to <tenantname>.budibase.app

_{From SyncLinear.com | BUDI-6570}