params.Frame: Add parameters for 3-D plots

[seisman]

This PR adds parameters for -B modifiers related to 3-D plots:

• +b: box
• +w: wall_pen
• +x: yzfill
• +y: xzfill
• +z: xyfill

GMT uses pen for +b (xref: https://github.com/GenericMappingTools/gmt/blob/ac580b28da697232ae21cfa2ec102610572af2d8/src/gmt_common_longoptions.h#L72), but I feel pen is too general, and it's also a little misleading because it only sets pen for x-z and y-z planes, not the frame pen for the x-y plane.

Example

import pygmt
from pygmt.params import Axis, Frame

fig = pygmt.Figure()
fig.basemap(
    region=(0, 1, 0, 2, 0, 3),
    projection="X10c/10c",
    zsize="5c",
    perspective=(120, 30),
    frame=Frame(
        axes="WSENZ",
        axis=True,
        zaxis=True,
        box=True,
        wall_pen="1p,red",
        xzfill="lightgreen",
        xyfill="lightblue",
        yzfill="lightyellow",
    )
)
fig.show()

Related to #4588