Follow up: consolidate cycle analytics URLs

What does this MR do?

• Moves the cycle analytics urls into the ee/api.js module
• Uses Api.buildUrl to generate the path
• Removes the SET_STAGE_ENDPOINT and SET_CYCLE_ANALYTICS_DATA_ENDPOINT vuex actions

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

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 #35206 (closed)

~backstage frontend ~"cycle analytics" analytics devopsmanage