(fix) O3-4964: Preserve translation builder edits with per-language cache

[Chinmay7070]

Requirements

• This PR has a title that briefly describes the work done including the ticket number. If there is a ticket, make sure your PR title includes a conventional commit label. See existing PR titles for inspiration.
• My work conforms to the OpenMRS 3.0 Styleguide and design documentation.
• My work includes tests or is validated by existing tests.

Summary

This PR refactors the Translation Builder to:

• Add per-language in-memory cache (localTranslations)
  to preserve user edits across language switches
• Add mergeTranslations(local, backend, fallback) utility
  function outside component with priority: local > backend > fallback
• Update handleUpdateValue to save edits to per-language cache
• Update languageChanger to check cache first before fetching backend
• Fix handleEditClick to remove duplicate setTranslations call

Screenshots

Before

openmrs-google-chrome-2026-02-27-22-24-14_DJ6SNEBe.mp4

After

openmrs-google-chrome-2026-03-06-19-17-51_B0Q2iUqc.mp4

Related Issue

https://openmrs.atlassian.net/browse/O3-4964

Other

Testing

• Verified language switching preserves edits
• Verified backend fetch happens only once per language

[Chinmay7070]

Hi Everyone,
please review the PR when you get a chance?
Thank you!

[Chinmay7070]

hi @denniskigen , @NethmiRodrigo
please review the PR when you get a chance?
Thank you!

[Chinmay7070]

hi @denniskigen
please review the PR when you get a chance?
Thank you!

[Chinmay7070]

hi @ibacher ,
please review the PR when you get a chance?
Thank you!