Tweaks for the Animation/ Track Editor

[heynoww]

The animation editor / track editor in the current version could use changes, and one in particular is being able to export and import individual tracks, along with their keys, as well as being able to choose what frame imported tracks will be in. I feel like this would save some hours of work, instead of manually having to insert a new key for each track in a joint. As of right now, there is no way to import/export tracks, and importing keys will reset progress on occasion, causing modified keys to become overwritten
Bringing back things such as the animation "Trim" feature, as well as being able to Hold Control to select multiple keys would be nice as well.