Coloring actions

Addresses https://github.com/KSHSK/WAVED/issues/206 (for coloring), https://github.com/KSHSK/WAVED/issues/239, https://github.com/KSHSK/WAVED/issues/255

Does not cover https://github.com/KSHSK/WAVED/issues/227

Edit 6/5: Sort of covers https://github.com/KSHSK/WAVED/issues/285 (the Properties panel one resets, but the action editor doesn't. Not a huge issue because the action editor won't let you save anyway if dataset is undefined and there are options for you to choose from)