coord_radial: add xlim and ylim arguments

[Yunuuuu]

Partial of #6259 (The feature request has been changed from set limits for coord_radial()).

Since coord_polar() does not have an expand argument, I have not implemented this for coord_polar().

ggplot(mtcars, aes(disp, mpg)) +
        geom_point() +
        coord_radial(
            start = -0.4 * pi,
            end = 0.4 * pi, inner.radius = 0.3
        )

ggplot(mtcars, aes(disp, mpg)) +
        geom_point() +
        coord_radial(
            start = -0.4 * pi,
            end = 0.4 * pi, inner.radius = 0.3,
            xlim = c(200, 300),
            ylim = c(15, 30),
            clip = "on"
        )

[teunbrand]

Thanks for the PR! For reasons mentioned in #6259 (comment), I oppose this proposal, so I'll leave the task of approving this PR to other maintainers.

[Yunuuuu]

Thanks for your feedback! I understand your concerns and will leave this open for further review by other maintainers.