Renaming/moving crates while importing files

Issue details:
If you rename a crate, or move it to a subcrate, while Scratch Live is still importing files to it (for example after dragging a folder to the crate list) then further files imported during the folder scan will not appear in the new crate.

Workaround:
When importing files by dragging folders into Scratch Live, ensure that the import process is complete before moving or renaming any crates. You can tell that Scratch Live has finished importing files by checking that the status bar at the bottom of the Scratch Live window no longer displays "Scanning Folder:" or "Reading Tags:"