feat(terminal/osc12): define cursor color through style of cell that describes the cursor position

The `.default` color will reset the cursor color to the terminal's default color

src/terminal.zig

@@ -42,6 +42,10 @@ pub fn showCursor() !void {
     _ = try posix.write(posix.STDIN_FILENO, ctlseqs.show_cursor);
 }
 
+pub fn resetCursorColor() !void {
+    _ = try posix.write(posix.STDIN_FILENO, ctlseqs.osc12_reset);
+}
+
 pub fn setCursorPositionHome() !void {
     _ = try posix.write(posix.STDIN_FILENO, ctlseqs.home);
 }