Scripts: restream: Save fine tuning config files by restreamer

[timotheeg]

Script was only storing config file by player 1 / player 2 from the raw template, which mean any fine tuning calibration being done for a particular user was lost at each game, which was super annoying.

This PR updates the restream script to store template files by twitch usernames. Restreaming the same user multiple times should be much faster now ✌️

Bonus:

• The config type check for float is a little too strict, now accepts floats and ints (needed for stream fps)
• Default template should read the line stats (field is not reliable considering random frame drops)

[timotheeg]

Thanks for the quick merge @alex-ong !