Data endpoint for tasks by type chart

What does this MR do?

Expose a dummy API response for the tasks by type chart. This change is behind a feature flag, the second MR will contain the real query object implementation.

• Example response: #32421 (comment 220979279)
• Feature: #32454 (closed)

The feature will consists of two charts, this MR sets up the first one, a few notes:

• Feature name: type of work analytics
• Charts: tasks by type AND tasks by stage (not included in this MR)
• Analytics features are EE only
• Each feature/component should have a feature flag

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Closes #32454 (closed)