Better warnings for old coords and new guides

[teunbrand]

This PR aims to fix #5707.

Briefly, both coord_map() and coord_polar() now throw a warning that they cannot render the relevant guides.

Reprex:

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

nz <- map_data("nz")
ggplot(nz, aes(x = long, y = lat, group = group)) +
  geom_polygon(fill = "white", colour = "black") +
  coord_map() +
  guides(x = guide_axis(angle = 45))
#> Warning: `coord_map()` cannot render guide for the aesthetic: x.

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  coord_polar() +
  guides(y = guide_axis(angle = 45), r = guide_axis())
#> Warning: `coord_polar()` cannot render guides for the aesthetics: y and r.

^{Created on 2024-02-23 with reprex v2.1.0}

[thomasp85]

LGTM