Update-Metadata - Safer workflow

[TheTaylorLee]

Topic Reason
Update-Metadata currently remuxes in the same directory as the source file. This presents some risks that would be mitigated if it followed similar workflows to the transcoding process.

Issues that would be mitigated

1. NFS locations would not be at risk of corruption due to dropped packets.
2. File watching applications like plex would not cause disruption during transcoding.
3. Disruptions during the remux process would result in the process not continuing until handled.

Changes to implement

• Create a temp database for logging file original locations. Needed for knowing where to put post processed file given update-metadata should not update the prod shows/movies tables beyond the existing contexts.
• Foreach file confirm fftools directories are empty
• Copy File into source process directory
• Write a table entry in the temp db with filename, fullpath, & tempname to avoid conflicts.
• Remux into target process directory
• Remove file from source process directory
• Move file from target process directory into processed directory.
• Check source, target, and processed directories are empty on next clean run of dta. If they are and temp db exists, delete it.
• Overwrite original file with file that is in processed directory. Match fullpath from the database to confirm target location where processed filename matches tempname.
• Update readme to remove update-metadata warning and instead just keep a warning about keeping backups.