[Feature Request] automatic clip backup

**Describe what you are trying to accomplish and why in non technical terms**
I want to be able to able to record to multiple locations to prevent losing storage should the Frigate NVR be stolen/taken during a robbery or the primary disk location dies such as in a hard drive failure.

**Describe the solution you'd like**
When it comes to specifying the storage location for recordings providing multiple locations should be possible such as NFS, SMB or FTP locations as well as the local disk location. Recordings should then be saved to both/all locations specified.

**Describe alternatives you've considered**
Alternatives would be to set this up at file level using OS file synchronisation (rsync, syncthing, nightly backups etc.) and have a job manually run to sync the locations although this is not ideal and the possibility for the redundant location to be out of sync by a couple of minutes/hours is quite large.

**Additional context**
Having redundant storage locations would be ideal to cover scenarios of theft of the actual NVR or a sudden failure of a mini PC's SSD. Additionally one could potentially configure this at a per camera level. This feature is available on NVR's such as hikvision where you can add a NFS mount and configure the camera's to store on both the local disk and remote location.

The issue names no files, tests, or entry points. Start by locating the recording storage configuration and the code that writes clips, then review how local, NFS, SMB, and FTP destinations could be represented. Done means recordings are reliably written to every configured destination, with the requested per-camera option clarified and tested.

Written by the indexing model from the issue text.