Annotate recipe

[jkrumbiegel]

This PR adds an annotate recipe which is a sort of hybrid between ggrepel, which annotates a bunch of points with labels that should avoid each other, and matplotlib-style annotations where arrows can be drawn from text labels to targets with lots of style options.

If an array of labels is given with no explicit text positions, labels are iteratively moved in order to overlap less with each other and the data points:

using Random

Random.seed!(123)
n = 30
points = randn(Point2f, n)
f, ax, sc = scatter(points)

ann = annotate!(ax, points;
    text = string.(rand(names(Base), n)),
    style = Ann.Styles.Line(),
)

f

Text positions can be given in data space or in offset space (default) so that it's easy to move the text just some visual distance away from the annotated thing.

f, ax, _ = lines(0..4, x -> cos(6x) * exp(x))
annotate!(ax, 2.1, 8, 1, 20, text = "local maximum", path = Ann.Paths.Arc(0.3), style = Ann.Styles.LineArrow(),
    labelspace = :data)
annotate!(ax, 2.65, -15, -50, -50,
    text = "local minimum", path = Ann.Paths.Arc(-0.3), style = Ann.Styles.LineArrow(
        head = Ann.Arrows.Head(),
    )
)
ax.xgridvisible = false
ax.ygridvisible = false
f

f, ax, _ = lines(0..10, sin)

annotate!(ax, pi/2, 1.0, 0, -100, text = "Peak", style = Ann.Styles.LineArrow())
annotate!(ax, 3pi/2, -1.0, 0, 100, text = "Trough", style = Ann.Styles.LineArrow())
annotate!(ax, 5pi/2, 1.0, -100, 0, text = "Second Peak", style = Ann.Styles.LineArrow(),
    path = Ann.Paths.Arc(-0.7),
    )

f

@ffreyer Ideally we could combine this with the textlabel recipe from #4879 somehow so that each label could have a background shape as well?

[MakieBot]

Benchmark Results

SHA: ef03e1f9b26c857f9f894fb2112375e162d2c07f

Warning

These results are subject to substantial noise because GitHub's CI runs on shared machines that are not ideally suited for benchmarking.

[briochemc]

I'd love this! Any reason preventing merging this?