Fixes #2.

Related upstream commits:
https://github.com/prusa3d/PrusaSlicer/commit/c3ce42a35a5b4a3425753ff6525f41716572fdba
https://github.com/prusa3d/wxWidgets/commit/a253c8943af931f0f6fd8492cd1ce9bdabef590a

Also attempts to fix FS#80091

This build includes wxWidgets dynamically linked, but vendored in a custom
location to be available for prusa slicer only.

The introduced patch allowed to pass options to wx-config which is
invoked during configure to determine the include in link directories.
The patch introduced the option, but quoted it incorrectly so that
wx-config got invoked with

'--toolkit=gtk3 --prefix=/build/prusa-slicer/src/wxwidgets-install/usr'

instead of

'--toolkit=gtk3' '--prefix=/build/prusa-slicer/src/wxwidgets-install/usr'

which lead to the prefix being omitted.
This commit also removes some options which are ignored by cmake
anyways, since unset early in FindwxWidgets.cmake.

+ make slicer-udev optional