Enable additional aesthetics in pitch annotation (`linewidth`, `alpha`, `linetype`)

This PR makes a few main changes to enable additional pitch aesthetics. Taken all together it's quite large, and I should have broken it up, but the key changes are more or less contained in a few commits which will be easier to browse than the full diff:

Use geom_curve to draw penalty box arcs (instead of drawing a full circle with grid::circleGrob): https://github.com/Torvaney/ggsoccer/commit/e991106a1c1a30a00cb630caff9375dc65b6d6a6
Add linewidth, alpha, linetype aesthetics to the arguments for annotate_pitch: https://github.com/Torvaney/ggsoccer/commit/8cb51b8e8dbfc2e3ec65f478fe0ad78e1b449755
Draw penalty- and six-yard boxes with 3 geom_segments (instead of geom_rect), so that there's no overlap with the whole-pitch outline (would interfere with linetype): https://github.com/Torvaney/ggsoccer/commit/a5e925f282f01344a706d5bbcdb2f634c6cac6a0

NB: I also used linewidth as the top-level aesthetic over size (https://github.com/Torvaney/ggsoccer/commit/0af098a0bd9e3e63c6da89df5c4115a951db4f54), since this was deprecated for lines in the latest ggplot2 release (3.4.0), although the points (penalty spots and centre point) take size = linewidth as well.

Some example images of what this looks like with different aesthetics:

library(ggplot2)
library(ggsoccer)

ggplot() +
  annotate_pitch(linewidth = 2) +
  theme_pitch()


ggplot() +
  annotate_pitch(linetype = "dashed") +
  theme_pitch()


ggplot() +
  annotate_pitch(colour = "white", linewidth = 1, linetype = "12", alpha = 0.1, goals = goals_line) +
  theme_pitch() +
  theme(panel.background = element_rect(fill = "steelblue"))

^{Created on 2022-11-30 with reprex v2.0.2}

Closes #10, closes #17, closes #18, and closes #23

Torvaney / ggsoccer

Enable additional aesthetics in pitch annotation (`linewidth`, `alpha`, `linetype`) #27