Add stylus support to window decoration and window focus

• Add tabletToolEvent() to DecorationEventFilter class so it can handle tablet events.
• Add tabletToolEvent() to MoveResizeFilter class to avoid incorrect titlebar highlight after a window is resized by using a stylus.
• Add tabletToolEvent() to WindowActionInputFilter class so window focus can be changed by clicking on the window content area when using a stylus.
• Add update() to TabletInputRedirection::tabletToolEvent() to enable switching window focus by using a stylus.

BUG: 432104

stylus-support-for-titlebar-h264

See also

!1647 (merged) !1696 (closed)

Known issues

• The titlebar must be clicked once to function normally.
• When the stylus hovers on the decoration at first, the content area will not respond to the stylus.
• The menu has a titlebar when clicking with a stylus. (not a regression, could be a Qt bug. https://bugs.kde.org/show_bug.cgi?id=445311)
• If kickoff (can't reproduce on other applets) is opened by touch for the first time after kwin_wayland starts, it will not respond to stylus hover events until clicking on it. (MouseArea in KickoffItemDelegate needs rework. https://bugs.kde.org/show_bug.cgi?id=445310)
• After moving a window, the content area will not respond to stylus (hover/click events) until clicking once.