BCK-3.2.2 - Video retention interval modification

Allow the database to receive a request which modifies the amount of time before a video gets deleted.

This amount should be capped at a certain value. This value is decided by the maximum amount of space the database has and the amount of space that one item takes.

For example, we can take the imperial value of "20 events a day". If every video chunk is 5min, then for how many more days can we save 5*20 = 100min of footage on the server. That is cap of time.

No files, tests, or entry points are named. Start by tracing how video deletion and database requests are currently handled, then clarify the storage-capacity and video-chunk assumptions with the maintainers. Done means a request can modify retention and the permitted interval is capped according to available space.

Written by the indexing model from the issue text.