1.12.2 CustomDifficultyLabel, Timing & Base64 Image

[UnskilledFreak]

• cover image will load from disc directly and get send as a image b64 string, if it fails it will use the coverurl from beatsaver
• audio timer uses a single timer that only runs when in song, it pulls the actual time of the audio file
• added SongCore as a dependency for coverImage
• added CustomDifficultyLabel property to StaticData, will be empty string if no custom label is set
• added TimeScale property to StaticData (this is usefull for calculating map length or modifier, its literaly just a float value representing the song speed eg 150% practice mode = 1.5, slower song = 0.85, faster song = 1.2, practice mode 50% will be 0.5 etc
• fixed accuracy calculation
• some code bueaty