refactor(group-analytics): Add project field to group type

[Twixes]

Problem

Step 6 of the environments implementation plan.

Changes

Added nullable field project to the GroupTypeMapping model. We now insert it in ingestion.

Backfill for existing group types will come in a separate PR.

How did you test this code?

All existing tests should continue to pass.

[oliverb123]

Hey @Twixes, have you checked how this interacts with property definitions? We rely on group-type mapping for certain property types. Not specific to this PR possibly, more the overall change

[oliverb123]

Just watched your brown-bag (nice one btw) and I feel like, if I understood correctly, this should remain at the "team (environment)" level? My gut says the set of group types is a property of the event data, rather than something users configure (hence why we create it on the fly during ingest rather than having users manually create it with some tagging rules, like an insight or dashboard).

I don't know that this is the right model for what a group type is, or whether we should make users declare them up front, but it is what it is today.

[Twixes]

Coming back to this now that some other PRs are in. To answer both your questions @oliverb123:

So, the concept behind environments is that data coming in/out is environment-specific, but the shape of that data lives at the project level – as it's the same instrumentation sending that data, only running in different environments. The same applies with event and property definitions, they define the shape (and users can configure them).
This PR here should not affect event/property definitions in any way. They're getting the project field too, but that'll be a separate PR.