…uest is moved from one folder to another but reappears when we close and reopen the app (fixes #345)

…lder, it should use the folder's parent but it doesn't happen as currentCollectionItem is always the request - even though the plugin is coming from the request's parent folder

…o another, then dragging it to the end of the original folder makes it disappear (fixes #343)

…oblem+xml should be considered as render-able types + change Binary Response Warning to Unknown Media Type Warning and also show media type in the warning (resolves #347)