Replaces all the json/config loading/saving functions with safe
variants to reduce the chance of potential file corruption as much as
possible.
Also does a minor refactor of json writing by using
obs_data_save_json_safe for writing json files instead of manually using
obs_data_get_json and os_quick_write_utf8 each time.
This makes it so that the log message for altering scene collections
and/or profiles is now below, and then the separator below that. This
makes it a bit more apparent that any loading/clearing/etc that happens
before the log message are associated with the log message.
Adds scene collections to the menu bar, which allows you to duplicate,
rename, remove, or add clean new scene collections.
Scene files are now stored in ./obs-studio/basic/scenes directory with
filesystem-safe names.
