[#50908] Implement redirect to project folder with waiting under /projects/:project_id/project_storages/:id/open

[ba1ash]

See feature for description: https://community.openproject.org/wp/50437
Link to the implementation chunk(no useful information there): https://community.openproject.org/work_packages/50908
Some technical implementation details worth mentioning:

1. A new flash message type has been introduced. A sample of usage:

       flash[:modal] = {
         type: 'Storages::OpenProjectStorageModalComponent',
         parameters: {
           project_storage_open_url: request.path,
           redirect_url: storage_open_url,
           state: :waiting
           }
         } 

   type is a class name for desired modal view_component.
   parameter are attributes that are passed to the modal class constructor.
2. The waiting modal has a polling mechanism implemented. It is located in storages/open-project-storage-modal.controller.ts.
   In short:
   1. It starts polling.
   2. Wait for response to arrive.
   3. Is it 200?
      1. Yes, then there is a turbo_stream in the body with updated modal content. Apply the turbo_stream. Stop polling.
      2. No, it returns to it starts from the beginning.
3. The logic that responds to the polling is located in storages/project_storages_controller.rb. Check the test for it: modules/storages/spec/requests/project_storages_open_spec.rb. I believe I was quite descriptive there.
4. Storage links in project menu has been updated to be `[ensure_connection_url]?destination_url=[project_storage_open_url]
5. To see the waiting modal locally you need to set nextcloud integration up, enable a project storage to be automatically managed, run a background synchronization job once, then add a user to the project, click on the link in a project menu, then there should be a waiting modal, then fire Nextcloud sync job again, the modal should be updated. Or contact me and let's test it together :)

[apfohl]

No major things to change. Mostly one 🟡 I would like you to change. The other 🟡 and 🟢 are just topics I would like to talk about with someone.