Provide upload progress indicator for attachments

Currently, when uploading a small attachments, it appears in attachment tab. However if file is large than 100MB even though it ends succesfully with a bit of time, the UI does not provide any visual feedback regarding the upload progress. As a result, users cannot easily determine whether the upload has started, is still in progress, or has failed.

Expectation that Cristal UI provides progress bar that improves user experience and transparency during uploads.