Add alignment and distribution icons

[ryankeairns]

Canvas has a current need for such icons (PR - elastic/kibana#39132) and it sounds like Lens could also use them.

The set would be similar to those found in Sketch:

Align
left | center | right | top | middle | bottom

Corner position
top left | top right | bottom left | bottom right

Distribute
horizontal | vertical

[ryankeairns]

How does this make you feel?

1px padding around each; the center and middle have 2px pad along one side to make the one-pixel bar intersect precisely at center of the rounded rectangle (which is 1px shorter in these two cases).

Preview

Sketch pixel grid

[cchaos]

LGTM! 👍