fix(#0090): replace remote datasource with PouchDB views for Select2 contact search

[hectorguillen-blip]

Description

Fixes the facility and associated contact Select2 dropdowns in the UserFormComponent, which were returning no results due to an incorrect data source.

Closes #13

Root cause

The original implementation used CHTDatasourceService with getRemoteDataContext() which requires contact_types to be configured in CHT settings to know which types to query. Most instances do not have this configured, causing the dropdowns to return empty results silently.

Changes

Select2SearchService

• Replaced CHTDatasourceService with DbService — queries PouchDB directly
• Uses medic-offline-freetext/contacts_by_type_freetext view for term-based search, matching the original AngularJS Select2Search service behaviour
• Falls back gracefully if the view is missing
• Results now display name, phone, and full parent lineage in gray — matching the original format.sender() output
• isContactInPlace now uses db.get().get() instead of the remote API

FreetextDesignDocService

• New service that checks for _design/medic-offline-freetext on app startup and creates it if missing
• Registered as an APP_INITIALIZER in app.config.ts so the view is available on every environment without manual setup

app.config.ts

• Added FreetextDesignDocService initializer

Tests

• Updated select2search.service.spec.ts to use DbService mock instead of CHTDatasourceService

Checklist

• Readable — follows style guide, ESLint passing
• Tested — unit tests updated to reflect new data source
• Backwards compatible — design doc is created automatically, no manual setup required