[recordings] Detect motion with aws lambda

[fantadrinker]

for uploaded video, process them, detect motions and save captured/updated video as new file

[fantadrinker]

steps:

1. highlight frame with squares, test on different videos.
2. potential improvements
3. trim video with timestamps

[fantadrinker]

actually I can probably do it in js. And do native download files. performance might be a problem so keep track of that