Copy angle heuristic for more guides.

[teunbrand]

This PR aims to fix #4594.

Briefly it copies the heuristic from guide_axis(angle) to the following guides: guide_colourbar(), guide_coloursteps() and guide_bins(). Note that angle heuristic is applied in GuideLegend$override_elements() even though GuideLegend does not use the heuristic (per https://github.com/tidyverse/ggplot2/issues/4594#issuecomment-1857460496). While not applied in GuideLegend, it is inherited by and used in child guides.

Some examples. Note that for labels placed close to the edge (1st example '6000'), the label may escape the allocated space, but there is no easy fix for this at the moment.

devtools::load_all("~/packages/ggplot2")
#> ℹ Loading ggplot2

p <- ggplot(msleep, aes(brainwt, sleep_total, colour = bodywt)) +
  geom_point(na.rm = TRUE)

p + guides(colour = guide_colourbar(angle = 45))

p + guides(colour = guide_coloursteps(angle = 45))

p + guides(colour = guide_bins(angle = 45))

^{Created on 2024-06-25 with reprex v2.1.0}