Integrate PA browser tool as football admin

Introduces the football admin utility that was previously in the
pa-browser repository.

Routing for the football admin is namespaced under /admin/football.

Bumps pa client to latest version to supprt the new features.
Integrate the tests for the football admin

This introduces the test data and sets up the TestClient to work in
the Frontend project.
Cache headers for the imported football admin Controllers
Add football admin links to Admin index
Add 2-team-focused table embed to football admin tool
Merge remote-tracking branch 'origin/master' into football-admin
Remove failing commercial healthcheck test
Merge branch 'football-admin-two-team-tables' into football-admin
Restore healthcheck test to merge master

Revert "Remove failing commercial healthcheck test"

This reverts commit 4ca73fbe858a4cfd5d9b83efe7678dfaf9890757.
Merge remote-tracking branch 'origin/master' into football-admin
Namespace football admin package

This separates the football admin tool into its own package.
Merge remote-tracking branch 'origin/master' into football-admin
Merge pull request #3106 from guardian/football-admin

Football admin