E2E ADO Migrations

[dylan-smith]

Orchestrates many of the steps needed to migrate repos from ADO to GitHub. Includes:

• Lock ADO repo (make it read-only)
• Migrate Repo
• Create AAD groups
• Add group members based on ADO permissions
• Provision groups to GitHub (SCIM)
• Create Teams / link AAD
• Rewire pipelines
• Configure Boards integration
• Configure Autolink References
• Disable ADO Repo (make it unreadable)
• Add teams to repo
• Set repo visibility
• Configure Dependabot / Secret Scanning
• Migrate branch policies
• Migrate required reviewers into CODEOWNERS

DRI: @dylan-smith

Batches

NOTE: The below are tasks, they need to be fleshed out still and grouped into batches.

• [ ] #44
• [ ] #42
• [ ] #10
• [ ] #9
• [ ] #5