AB#134285 - ABC - Improve system to switch language

[Joselgc1]

Description

Adds a language switcher to the shared application header so users can quickly change the platform language without opening preferences.

Useful links

• https://dev.azure.com/WHOHQ/EMSSAFE/_workitems/edit/134285/

Type of change

• New feature (non-breaking change which adds functionality)
• Improvement (refactor or addition to existing functionality)

How Has This Been Tested?

The following checks were run locally:

• NODE_OPTIONS="--max-old-space-size=4096" npx nx lint shared
• NODE_OPTIONS="--max-old-space-size=4096" npx nx test shared --testPathPattern=layout.component.spec.ts --runInBand

Manual verification:

• Confirmed the language switcher appears in the shared header when multiple languages are available.
• Confirmed the switcher is positioned to the right of the notification bell.
• Confirmed the current language is not displayed in the dropdown list.
• Confirmed language options use the expected <current language value> / <other language value> format.
• Confirmed selecting a language saves it and reloads the page.

Screenshots

Checklist:

( * == Mandatory )

• * I have set myself as assignee of the pull request
• * My code follows the style guidelines of this project
• * Linting does not generate new warnings
• * I have performed a self-review of my own code
• * I have put the ticket for review, adding the oort-frontend team to the list of reviewers
• * I have commented my code, particularly in hard-to-understand areas
• * I have put JSDoc comment in all required places
• * My changes generate no new warnings
• * I have included screenshots describing my changes if relevant
• * I have selected labels in the Pull Request, according to the changes with code brings
• I have made corresponding changes to the documentation ( if required )
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules