Redesign node icons

[Keavon]

We need to come up with a design language for node icons. Then we can replace these ones for folders and vector shapes (among other future ones, that aren't needed yet in the app but are needed in the design mockups).

[0HyperCube]

@Keavon Also for text layer (will work on that next)

[Keavon]

Excellent, that's exciting to hear! Let's touch base on that before you resume.