Image database methods should not resolve the effective project

[markylaing]

While working on #13886, I added an extra query to many image and image alias endpoints to resolve the effective project for images, as required for authorization checks.

For all other entity types with a features.{entity_type} project configuration, a helper function exists in the project package to resolve the effective project. This is set in the request context and used in database queries. However, the image database queries expect the request project, and resolve the effective project as part of the query. This is no longer necessary.

Additionally, some methods seem redundant (GetImage appears to just call GetImageByFingerprintPrefix).

We should revisit some of these methods and clean them up.