mhv-67886 added feature flag

[KolbyVA]

Summary

Adds feature flag for new medical records feature flag for filter and sort functionality.

Related issue(s)

https://jira.devops.va.gov/browse/MHV-67886

Create Feature Flag for Filter/Sort Functionality

Figma Link: https://www.figma.com/design/SGP1z2LejUWqDZyT61po5J/Medical-Records---Phase-1?node-id=15772-264342&t=CKtiLMsVTpl4ZWpS-4

Testing done

None needed

Screenshots

Note: Optional

What areas of the site does it impact?

(Describe what parts of the site are impacted andifcode touched other areas)

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog (if applicable)
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature

Requested Feedback

(OPTIONAL)What should the reviewers know in addition to the above. Is there anything specific you wish the reviewer to assist with. Do you have any concerns with this PR, why?