Resolve "Value Stream Analytics - Move recent activity to separate module"

What does this MR do?

The first iteration of value stream analytics used a single endpoint to return the stages and summary data, since the stages are needed in various places through value stream analytics, the best place to store the summary (recent activity) data was in the vuex store along with the stages, ensuring we could update the summary data when the shared endpoint finished returning data.

The next iteration separated these 2 endpoints, so we could fetch the summary data independently of the stages, we kept the data in the vuex store, but we split the actions and mutations.

We no longer need to store the data in the vuex store since the recent activity component is the only place we require this data, and we have a dedicated endpoint for fetching it.

• Rename summary table to recent activity card
• Fetch activity data from within the component
• Ensures the recent activity card does not need to wait for the rest of the value analytics initial requests to start rendering
• Replaces the custom summary table with the shared metric card
• Removes all vuex state / actions / mutations for fetching recent activity as the data now has an individual endpoint (which was not the case when it was initially implemented)

Screenshots

No visual changes

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

Closes #197334 (closed)