Add Figure.magnetic_rose to plot a magnetic rose on map

[seisman]

This PR implements the Figure.magnetic_rose method to plot a magnetic rose. It wraps the basemap/coast's -Tm option.

Preview: https://pygmt-dev--4051.org.readthedocs.build/en/4051/api/generated/pygmt.Figure.magnetic_rose.html

The GMT CLI syntax is

-Tm[g|j|J|n|x]refpoint[+ddec[/dlabel]]][+ipen][+jjustify][+l[w,e,s,n]][+ppen][+tints][+odx[/dy]][+wwidth]

The Pythonic long-form parameters are:

• [g|j|J|n|x]refpoint[+jjustify][+odx[/dy]]: position
• +w: width
• +p: outer_pen
• +i: inner_pen
• +l: labels
• +d: declination, declination_label
• +t: intervals

Examples

importpygmtfrompygmt.paramsimportPositionfig=pygmt.Figure()
fig.basemap(region=[-10, 10, -10, 10], projection="M15c", frame=True)
fig.magnetic_rose(
position=Position((-5, -5), cstype="mapcoords"),
width="4c",
labels=["W", "E", "S", "*"],
intervals=(45, 15, 3, 60, 20, 4),
outer_pen="1p,red",
inner_pen="1p,blue",
declination=11.5,
declination_label="11.5°E",
)
fig.show()

Addressing #2831.

[seisman]

@yvonnefroehlich Please review #4014 first. I'll make further changes to this PR when PR #4014 is finalized.

[github-actions]

Summary of changed images

This is an auto-generated report of images that have changed on the DVC remote

Status	Path
added	pygmt/tests/baseline/test_magnetic_rose.png
added	pygmt/tests/baseline/test_magnetic_rose_complete.png

Image diff(s)

Details

Added images

• test_magnetic_rose.png

• test_magnetic_rose_complete.png

Modified images

Path	Old	New

Report last updated at commit 5dcd644

[seisman]

This PR is also ready for review. The key point that we need to discuss is the default position.

As shown below, GMT's default position is x0/0, which looks bad. In PyGMT, the default is jBL which looks pretty good. Need to note that there are some GMT issues with the box.

gmt begin positions png
gmt basemap -R0/20/0/10 -JX20c/10c -Baf
gmt basemap -Tm+w2c
gmt basemap -TmjBL
gmt basemap -TmjBR -F
gmt end show

[yvonnefroehlich]

Around line 44: Need to add this high-level method to the list after merging the PR for Figure.directional_rose.