Write DomainMetrics and add FF to switch reads from calculated properties

[nospame]

Technical Summary

SAAS-16283

Writes "calculated properties" currently stored on the Domain Elasticsearch doc to the new DomainMetrics SQL model and adds a feature flag so that reads can be switched from the ES doc to the SQL model once populated. This is part 2 of 3 for moving calculated properties into SQL, following #35415. This should be reviewable by commit.

Feature Flag

Adds the slightly wordy CALCULATED_PROPERTIES_FROM_DOMAIN_METRICS feature flag, which can be used to switch calculated properties reads over to the SQL model for a single domain, to toggle on for all domains.

Safety Assurance

Safety story

This doesn't affect existing data or the write process for calculated properties on the ES doc. Reading from the new model is controlled by a feature flag, so if there are any issues after switching over, it can easily be switched back.

Automated test coverage

Adds automated tests for identifying the correct project spaces to have their DomainMetrics updated. These are based on existing tests that look to see the right domains will get their calculated properties updated.

QA Plan

I can see an argument for QA, but not planning it at this time. I think dev testing on staging will suffice.

Migrations

• The migrations in this code can be safely applied first independently of the code

Rollback instructions

• This PR can be reverted after deploy with no further considerations

Labels & Review

• Risk label is set correctly
• The set of people pinged as reviewers is appropriate for the level of risk of the change