Ability to Auto-Upload certain file types only

### Is your feature request related to a problem? Please describe.
I would like to have the Auto-Uploads only for certain file types in certain folders. Currently, it also grabs many `.tmp` files that are created before the full file is available in the target folder for Nextcloud to grab.

### Describe the solution you'd like
In the Auto-Uploads settings for a particular folder, an option of "All files", or "exclude filetypes \[text box here\]"

### Describe alternatives you've considered
An app I need this for does not have an alternative - where it writes the `.tmp` files is where the final files are (`.aac`) that I want backed up.

### Additional context
Unsure what else to offer, but I'd love to help this if possible.