Add product analytics models

What does this MR do?

Extracting AR models from !27730 (closed).

DB changes are already merged in !35168 (merged)

The feature will be behind feature flag and disabled by default

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry (not needed, feature is disabled by default)
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content