Add an option for a filter command

[evancharlton]

When importing many files (especially from generated backups), there are often files which aren't really worth importing. For example, an old photo library might include many thumbnails, and these low-resolution images don't really belong in my fancy new Immich installation.

This change adds a --filter <cmd> argument to the upload command. This allows the user to pass in a command to be executed (which will be passed the full filename as the first argument). If this command (plus file) returns a non-zero exit code, the file will not be processed by the upload script.

Examples

For the below examples, assume that there exists a script called demo.sh (and is executable) in the current directory.
It would be used like this: upload --filter "./demo.sh".

Exclude thumbnails

#!/usr/bin/env bash
# demo.sh

grep -q -v _thumb <<< "$1"

Exclude low-resolution images

#!/usr/bin/env bash
# demo.sh

W=$(exiftool -ExifImageWidth "$1" | awk -F' : ' '{print $2}')
H=$(exiftool -ExifImageHeight "$1" | awk -F' : ' '{print $2}')

(( $W > 800 )) && (( $H > 800 ))

[evancharlton]

This has a similar objective to #91, but offers more flexibility in terms of allowing the script to do anything -- including file introspection.