feat(issues): infer project platform if not set

[cvxluo]

If a project ends up with no platform (e.g. by API creation), we attempt to infer it from its events. We go by the following:

1. if a project has a non-null platform that we did not previously infer, do not do anything
2. if a project has no platform, set platform to the next event platform it receives
3. if a project has a platform that we've previously inferred and it receives an event that does not match that platform, set the project platform to other

This creates a new project option sentry:project_platform_inferred, which is set to the inferred platform.

Related:

• https://linear.app/getsentry/issue/ID-442/investigate-and-fix-projects-with-no-platform
• Investigate and fix projects with no platform #82176

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

✅ All tests successful. No failed tests found.

Additional details and impacted files

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