feat(analytics-chart): experimenting with legend styling

[mihai-peteu]

Summary

@filipgutica This is an attempt to simplify the Legend height conundrum, and keep it styled via pure CSS (thus allowing us to do away with the bound CSS variable).

Using color squares instead of lines, and also left-aligning the legend (roughly in line w/ the Y-Axis labels)

Resources

• Creating a package docs

[filipgutica]

Sometimes still overlapping in some situations and also sometimes not showing the second row

Also, when it wraps to a new line, should there be more space between rows?

[filipgutica]

There's still some weirdness with the spacing of the legend items, some legend color tags also don't show up or are getting cut off?

On this branch

Vs on dev:

[mihai-peteu]

Closing in favor of #1462

But the legendAsGrid mixin could prove useful in the future...