Adjust redis cache metrics

What does this MR do?

Adjust the redis cache metrics to be more useful.

• Remove controller and action labels from duration histogram.
• Create a new simple counter for controller and action.
• Adjust histogram buckets to observe smaller response times.

First step in https://gitlab.com/gitlab-org/gitlab-ce/issues/64064

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance 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