User Blocked Page in Self-Hosted Instance Advises User To Contact Gitpod.io Support

Bug description

When a user is blocked in a self-hosted instance they're shown a page that lets them know they're blocked with a button to 'Contact Support' and a link to review the Terms of Service on the Gitpod website.

We likely need to allow instance administrators to set an email address of their own or URL which can be used in these sorts of situations where the user is being told to contact support.

Steps to reproduce

1. Spin up a self-hosted instance - using 2022.05.2.
2. Create a few users and block one of them.
3. Login as the blocked user and attempt to spin up a workspace.
4. Observe the page telling you you're blocked and that you can view the Terms of Service and a Contact Support button. Note these link to Gitpod.io.

Workspace affected

No response

Expected behavior

I would expect in a self-hosted environment I can view the terms of service for that environment, and when clicking on Contact Support that I am contacting the support of that instance, not Gitpod.io.

Example repository

No response

Anything else?

I believe the related code is here - https://github.com/gitpod-io/gitpod/blob/c2a621ef64571a26805fe7f1ffb2d4cea3accf42/components/dashboard/src/App.tsx#L299

Start in components/dashboard/src/App.tsx around line 299, then trace how the blocked-user page obtains its Terms of Service and Contact Support links. Check how self-hosted instance settings are represented before determining where instance-specific values belong. Done means blocked users in self-hosted environments see that instance's terms and support destination rather than Gitpod.io links.