Fixing some warnings due to union types

[joehan]

Description

Fixing up some issues from the recent 'ajv' upgrade - namely:

• AllowUnionTypes:true - typescript-json-schema can generate these, so we need to allow them.
• Actually depend on ajv-formats - this slipped past our no-undeclared-imports check because it was a require before.

Scenarios Tested

Before:

After:

[bkendall]

Looks like you've got some issues to sort out before this is ready... :/

[joehan]

Looks like you've got some issues to sort out before this is ready... :/

I believe most of these failures were actually caused by an NPM outage today - rerunning the tests now to confirm. Will fix and rerequest later if there are still issues

[joehan]

The test failures are unrelated and on non-blocking tests. The VSCode failures should be fixed by #8107 and #8108 , and the data connect e2e test is flaky.

[bkendall]

Seems fine to me - though there's a lot removed from firebase-config, so maybe just confirm that that's cool

[joehan]

Seems fine to me - though there's a lot removed from firebase-config, so maybe just confirm that that's cool

Sanity checked it and it looks like it is still working correctly. The reduced file length is because the new version of typescript-json-schema makes (much) better use of $ref to avoid redundancies.