Add API to increment Redis HLL counter on user_id and metric

What does this MR do?

Add UsageData API

Add increment_unique_values API which is incrementing unique values for given event_name

More context #232831 (closed)

Possible usage, to track UI events, for example distinct users count that clicked on Expand button on MRs

This is using Redis HLL

Problem to solve

Be able to increment unique values for UI events

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related #235459 (closed)