Blender Git Loki

Fix T83930 and Fix T84659: Walk navigation tablet bugs.

Fixes T83930, allowing walk navigation to continue without jumping back
after repositiong pen.

Fixes T84659, allow walk navigation to start (for Windows Ink) from
keyboard shortcut when pen is in use.

Windows high frequency Wintab input.

Use Wintab supplied mouse movement once verified against system input,
checked by comparing Win32 and Wintab button down event positions.

Dynamically unload Wintab if Tablet API is WinPointer (Windows Ink),
load Wintab otherwise.

When Tablet API is Automatic, dynamically switch between Wintab and
WinPointer based on number of Wintab devices present. Previous
behavior was to use Wintab if wintab.dll was present on system.

Allow system handling of system cursor movement during WinPointer
events by leaving WM_POINTERUPDATE events unhandled.