Migrate `HomepageSearchCache` to v2

[maxachis]

Context

• The HomepageSearchCache exists in a weird liminal space where it's an endpoint in v1 but not in v2.
• While this has worked temporarily, we'll need to migrate it into v2 and bring it into compliance with the various tests and documentation standards we've set up there.

Requirements

• Bring HomepageSearchCache and associated middleware to v2
• Set up tests and docs for it as needed.
• Revise permissions structure to v2 standards.

Tests

• Build basic middleware, DatabaseClient, and integration tests

Docs

• Set up swagger documentation for endpoint

Open questions

• None at this time!

[josh-chamberlain]

@maxachis nice. What do you think about a "graceful" deprecation period for the v1 API where we remove endpoints that are replaced via v2? Or, do you think we should just be ready to do it all at once?

[maxachis]

@maxachis nice. What do you think about a "graceful" deprecation period for the v1 API where we remove endpoints that are replaced via v2? Or, do you think we should just be ready to do it all at once?

I think we can do so gradually! We lose nothing but a little bit of hosting cost from having two apps simultaneously, and we'll be able to minimize friction if we can do things one at a time without being in a rush.