UI: Capitalize "Python" in UI messages, improve a few others

- "... (matches pythons ...)": capitalize and use possessive ('s).
- "Layer Proxy Protection": replace proxy by override, following 2.80.
- "Enable Plane Trim": expand description.
- "Make curve path children to rotate along the path": remove "to".
- "Option for curve-deform: make deformed child to stretch along
  entire path": remove "to".
- "... apply the curve radius with path following it and deforming":
  rephrase unclear description.
- "Custom light falloff curve" : unrelated to lights, used in Grease
  Pencil modifiers.
- "Grease Pencil layer assigned to the generated strokes": rephrase
  because a GP stroke is assigned to a layer, not the other way
  around.
- "Attribute domain where the attribute domain is stored in the
  simulation state": remove second "domain" (typo).

Pull Request: blender/blender#107916

source/blender/python/intern/bpy_interface.c

@@ -410,7 +410,7 @@ void BPY_python_start(bContext *C, int argc, const char **argv)
       else {
         /* Set to `sys.executable = None` below (we can't do before Python is initialized). */
         fprintf(stderr,
-                "Unable to find the python binary, "
+                "Unable to find the Python binary, "
                 "the multiprocessing module may not be functional!\n");
       }
     }
@@ -427,7 +427,7 @@ void BPY_python_start(bContext *C, int argc, const char **argv)
         if (strchr(py_path_bundle, ':')) {
           fprintf(stderr,
                   "Warning! Blender application is located in a path containing ':' or '/' chars\n"
-                  "This may make python import function fail\n");
+                  "This may make Python import function fail\n");
         }
 #  endif /* __APPLE__ */