[MM-56616] Changes for the DM for batch reporting (#26019)

* [MM-56616] Changes for the DM for batch reporting

* Use requesting user's locale

* Fix lint

* Remove unnecessary test

* Move back to file attachment

* Add default API case

* Fix i18n

* Hardcode the CSV string

api/v4/source/reports.yaml

@@ -195,42 +195,3 @@
           $ref: "#/components/responses/Forbidden"
         "500":
           $ref: "#/components/responses/InternalServerError"
-  /api/v4/reports/export/{report_id}:
-    get:
-      tags:
-        - reports
-      summary: Retrieves a compiled report file for the given report_id
-      description: >
-        Retrieves a compiled report file for the given report_id.
-
-        Must be a system admin to invoke this API.
-        
-        ##### Permissions
-        
-        Requires `sysconsole_read_user_management_users`.
-      
-      operationId: RetrieveBatchReportFile
-      parameters:
-        - name: report_id
-          in: path
-          description: Report ID for the given batch job
-          required: true
-          schema:
-            type: string
-        - name: format
-          in: query
-          description: The format of the report generated (one of "csv")
-          required: true
-          schema:
-            type: string
-      responses:
-        "400":
-          $ref: "#/components/responses/BadRequest"
-        "401":
-          $ref: "#/components/responses/Unauthorized"
-        "403":
-          $ref: "#/components/responses/Forbidden"
-        "404":
-          $ref: "#/components/responses/NotFound"
-        "500":
-          $ref: "#/components/responses/InternalServerError"