Added a layer keyframe dropdown menu

This is the first updated feature of my motion graphics software “Before Effects”. I was really annoyed by the old layer system where you know where the keyframes are, but not what attributes are keyed. This is now fixed!

Features

• Added a default path on start so I could debug easily
• Added a clickable dropdown arrow. When clicked, it shows a bunch of sub-layers named by their corresponding attributes
• Renamed a lot of variables and functions as a result of my spaghetti-coding habits

I still need to draw the keyframe diamonds on their correct sub-layers.