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

[Torvaney]

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): e991106
• Add linewidth, alpha, linetype aesthetics to the arguments for annotate_pitch: 8cb51b8
• 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): a5e925f

NB: I also used linewidth as the top-level aesthetic over size (0af098a), 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.

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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}

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

[Torvaney]

@lvanden - I can't add you as a reviewer (I think I might need to add you as a "collaborator" or something for that?), but I thought I'd put this up as a PR in case you wanted to have a look.

(It's a little late, but in my defence, I didn't say which Christmas break I would have some time in! 😅)