Code review for potsanity 3.0

Mostly code style fixes (including some not directly related to this PR, but I figured I might as well include them). Other changes:

Added a longer comment to the audio thread address bump
Added ASM/src/drop_overrides and ASM/src/hacks directories to CI
Removed an ambiguous cryptic hint
Changed the IGNORE_LOCATION placeholder item from Recovery Heart to Nothing
Moved new scene flags.txt into the Notes directory
Made the Big Octo preview behavior for a Nothing item match that for no location
Removed the special casing for starting with Recovery Heart, Nothing, or Fairy Drop and used the same mechanism used for other starting items instead

rrealmuto / OoT-Randomizer