refactor: track current xcursor using an enum, instead of a char pointer

cursor-shape.h

@@ -0,0 +1,21 @@
+#pragma once
+
+enum cursor_shape {
+    CURSOR_SHAPE_NONE,
+    CURSOR_SHAPE_CUSTOM,
+
+    CURSOR_SHAPE_HIDDEN,
+    CURSOR_SHAPE_LEFT_PTR,
+    CURSOR_SHAPE_TEXT,
+    CURSOR_SHAPE_TEXT_FALLBACK,
+    CURSOR_SHAPE_TOP_LEFT_CORNER,
+    CURSOR_SHAPE_TOP_RIGHT_CORNER,
+    CURSOR_SHAPE_BOTTOM_LEFT_CORNER,
+    CURSOR_SHAPE_BOTTOM_RIGHT_CORNER,
+    CURSOR_SHAPE_LEFT_SIDE,
+    CURSOR_SHAPE_RIGHT_SIDE,
+    CURSOR_SHAPE_TOP_SIDE,
+    CURSOR_SHAPE_BOTTOM_SIDE,
+};
+
+const char *cursor_shape_to_string(enum cursor_shape shape);