input settings: Allow disabling stylus buttons.

ref:
linuxmint/cinnamon-control-center@3754965c5d393448e1
linuxmint/cinnamon-desktop@610a006d86d1f6

https://github.com/orgs/linuxmint/discussions/189

Author: mtwebster

src/backends/native/meta-input-settings-native.c

@@ -547,6 +547,8 @@ action_to_evcode (CDesktopStylusButtonAction action)
       return BTN_BACK;
     case C_DESKTOP_STYLUS_BUTTON_ACTION_FORWARD:
       return BTN_FORWARD;
+    case C_DESKTOP_STYLUS_BUTTON_ACTION_DISABLED:
+      return BTN_DEAD; // This needs testing under wayland?
     case C_DESKTOP_STYLUS_BUTTON_ACTION_DEFAULT:
     default:
       return 0;

src/backends/x11/meta-input-settings-x11.c

@@ -901,6 +901,8 @@ action_to_button (CDesktopStylusButtonAction action,
       return 8;
     case C_DESKTOP_STYLUS_BUTTON_ACTION_FORWARD:
       return 9;
+    case C_DESKTOP_STYLUS_BUTTON_ACTION_DISABLED:
+      return 0;
     case C_DESKTOP_STYLUS_BUTTON_ACTION_DEFAULT:
     default:
       return button;