feat: allow Isomer admins to edit on email-login and adjust permissions

[dcshzj]

Problem

Closes IS-654.

Solution

Breaking Changes

• [ ] Yes - this PR contains breaking changes
• [x] No - this PR is backwards compatible with ALL of the following feature flags in this doc

Features:

• A new collaborator role ISOMERADMIN has been added to identify users in the IsomerAdmins table. This additional role allows Isomer admins to have access to sites and act as if they are an admin of that particular site.

Improvements:

• The logic for the review request summary has been updated to reject GitHub login users if the site has already been migrated. This is to prevent GitHub users from editing their existing sites after we migrate them from GitHub to email login, and to encourage them to edit using their email-login account.

Tests

• Unit tests
• Smoke tests (on https://github.com/isomerpages/isomercms-frontend/pull/1604)

Deploy Notes

None

[kishore03109]

@dcshzj hmm wait we already have a table for isomer_admins, why not just make anyone who is an isomer_admin admin for all sites ah? this way we dont have to maintain a map of site_memeber_admins -> sites bah

[dcshzj]

@dcshzj hmm wait we already have a table for isomer_admins, why not just make anyone who is an isomer_admin admin for all sites ah? this way we dont have to maintain a map of site_memeber_admins -> sites bah

Hmm @kishore03109 are you able to clarify your comment? I'm using this table to determine who is an Isomer admin and enhancing existing endpoints to be able to retrieve this information from this isomer_admin table, so there is no adjustments made to the site_members table.

[kishore03109]

Dont merge in today ya, we upgrading version today