Figure.coast: Migrate the land/water parameters to the new alias system (#4241)

Co-authored-by: Yvonne Fröhlich <94163266+yvonnefroehlich@users.noreply.github.com>

Author: seisman

pygmt/src/coast.py

@@ -24,18 +24,18 @@
     A="area_thresh",
     C="lakes",
     E="dcw",
-    G="land",
     I="rivers",
     L="map_scale",
     N="borders",
-    S="water",
     W="shorelines",
 )
-def coast(
+def coast(  # noqa: PLR0913
     self,
     resolution: Literal[
         "auto", "full", "high", "intermediate", "low", "crude", None
     ] = None,
+    land: str | None = None,
+    water: str | None = None,
     box: Box | bool = False,
     projection: str | None = None,
     frame: str | Sequence[str] | bool = False,
@@ -70,8 +70,10 @@ def coast(
        - B = frame
        - D = resolution
        - F = box
+       - G = land
        - J = projection
        - R = region
+       - S = water
        - V = verbose
        - c = panel
        - p = perspective
@@ -97,8 +99,10 @@ def coast(
         ``"low"``, and ``"crude"``, which drops by 80% between levels. Default is
         ``"auto"`` to automatically select the most suitable resolution given the chosen
         map scale.
-    land : str
+    land
         Select filling of "dry" areas.
+    water
+        Select filling of "wet" areas.
     rivers : int, str, or list
         *river*\ [/*pen*].
         Draw rivers. Specify the type of rivers and [optionally] append
@@ -149,8 +153,6 @@ def coast(
         - ``3``: marine boundaries
         - ``"a"``: all boundaries (``1`` - ``3``)
 
-    water : str
-        Select filling "wet" areas.
     shorelines : bool, int, str, or list
         [*level*\ /]\ *pen*.
         Draw shorelines [Default is no shorelines]. Append pen attributes
@@ -201,10 +203,15 @@ def coast(
     >>> fig.show()
     """
     self._activate_figure()
-    if not args_in_kwargs(args=["C", "G", "S", "I", "N", "E", "Q", "W"], kwargs=kwargs):
+
+    if (
+        kwargs.get("G", land) is None
+        and kwargs.get("S", water) is None
+        and not args_in_kwargs(args=["C", "I", "N", "E", "Q", "W"], kwargs=kwargs)
+    ):
         msg = (
             "At least one of the following parameters must be specified: "
-            "lakes, land, water, rivers, borders, dcw, Q, or shorelines."
+            "land, water, lakes, rivers, borders, dcw, Q, or shorelines."
         )
         raise GMTInvalidInput(msg)
 
@@ -222,6 +229,8 @@ def coast(
             },
         ),
         F=Alias(box, name="box"),
+        G=Alias(land, name="land"),
+        S=Alias(water, name="water"),
     ).add_common(
         B=frame,
         J=projection,