feat: add get publishing endpoint (CT-000) (#428)

<!-- You can erase any parts of this template not applicable to your Pull Request. -->

**Fixes or implements VF-000**

### Brief description. What is this change?
Added a new endpoint: 
`GET /public/:projectID/publishing` - this fetches the `version.platformData.publishing` field of a PUBLIC project

because of the `resolvePublicProjectID` middleware, the project's `project.apiPrivacy` must be public to get this information. This is important to expose because it allows us to fetch project settings and metadata from the adapters/clients.

Co-authored-by: Tyler Han <tylerhan97@gmail.com>

backend/api/routers/public.ts

@@ -18,5 +18,7 @@ export default (middlewares: MiddlewareMap, controllers: ControllerMap) => {
     controllers.stateManagement.publicInteract
   );
 
+  router.get('/:projectID/publishing', interactMiddleware, controllers.stateManagement.getPublicPublishing);
+
   return router;
 };

lib/controllers/stateManagement/index.ts

@@ -68,6 +68,17 @@ class StateManagementController extends AbstractController {
     return { trace };
   }
 
+  @validate({
+    HEADERS_VERSION_ID: VALIDATIONS.HEADERS.VERSION_ID,
+  })
+  async getPublicPublishing(req: Request<{ userID: string }, never, { versionID: string }>) {
+    const api = await this.services.dataAPI.get();
+
+    const version = await api.getVersion(req.headers.versionID);
+
+    return version.platformData.publishing || {};
+  }
+
   @validate({ HEADERS_PROJECT_ID: VALIDATIONS.HEADERS.PROJECT_ID })
   async get(req: Request<{ userID: string }, any, { projectID: string }>) {
     return this.services.session.getFromDb(req.headers.projectID, req.params.userID);