[FR] control padding inside legend

[ptoche]

Feature request: add the option to increase padding inside legend, particularly to avoid labels overlap. Fine control over horizontal/vertical spacing would be even better, but a general padding argument would probably cover most cases.

The issue is described here with a workaround. Code copied for convenience.

using LaTeXStrings, Plots; gr()

y1, y2 = rand(100), rand(100)
histogram(y1, ylims = (0,50), label = L"\left\Vert\beta_{1}^{2}-\beta_{2}^{2}\right\Vert")
histogram!(y2, label = L"\left\Vert\beta_{2}^{2}-\beta_{3}^{2}\right\Vert", legendfontsize=10)