feat(project-currency): implement project-specific currency support

- Added a currency column to the projects table to allow different projects to use different currencies.
- Updated existing projects to default to 'USD' if no currency is set.
- Enhanced project finance controller to handle currency retrieval and updates.
- Introduced API endpoints for updating project currency with validation.
- Updated frontend components to display and manage project currency effectively.

worklenz-backend/database/sql/4_functions.sql

@@ -5401,7 +5401,8 @@ BEGIN
         updated_at             = CURRENT_TIMESTAMP,
         estimated_working_days = (_body ->> 'working_days')::INTEGER,
         estimated_man_days     = (_body ->> 'man_days')::INTEGER,
-        hours_per_day          = (_body ->> 'hours_per_day')::INTEGER
+        hours_per_day          = (_body ->> 'hours_per_day')::INTEGER,
+        currency               = COALESCE(UPPER((_body ->> 'currency')::TEXT), currency)
     WHERE id = (_body ->> 'id')::UUID
       AND team_id = _team_id
     RETURNING id INTO _project_id;