Force analyze files

[36grad]

Add an option (--force_analyze_files) that enablee the user to explicitly (re-)analyze specific files.

- The  --force_analyze_files option allows the user to specify files that they want to analyze.
- The  --force_analyze_files (or -f) option can be used multiple times to analyze more than one file.
- The images must be given relative to the data/USER_ID/files folder and thus the --user_id option is required.
- The  --force_analyze_files option does not work together with sync-mode or cluster-mode.
- If no mode is specified by the user, defer-mode is enabled for a better user experience.
- Files that are specified using the  --force_analyze_files option are put at the front of the analysis queue and thus are analyzed first.