Add supported filetypes, add various tests/fixtures

quick little hotfix as i forgot to

• add the sample mp4 into the fixtures folder, and fix some syntax for the library_media.rb
• fix extract.rb logic to validate specific video/audio/caption files
• create tests to check valid filetypes
• create tests to check proper file type management (moving respective files to completed/, pending/, error/)
• add fix for weird interaction with M1 macs and open telemetry, specifically protobuf