guix: qt-build-system, qt-utils: Unify wrapping of qt-programs.

guix: qt-build-system, qt-utils: Unify wrapping of qt-programs.

Unify (guix qt-build-system wrap-all-programs) and
(guix qt-utils wrap-qt-program), so both behave the same.
The functions now reside in qt-utils to make them easily available for
packages not using the qt-build-system.

* guix/build/qt-build-system.scm (variables-for-wrapping, wrap-all-programs):
  Move from here ...
* guix/build/qt-utils.scm (variables-for-wrapping, wrap-all-qt-programs):
  ... to here. Base the later on
  (wrap-qt-program*): New function, carved out from old wrap-all-programs.
  (wrap-qt-program): Base on wrap-qt-program*, change arguments in an
  incompatible way.
* gnu/packages/bittorrent.scm (qbittorrent)[arguments]<phases>{wrap-qt}:
  Adjust to new interface of wrap-qt-program.
* gnu/packages/finance.scm (electron-cash): Likewise.
* gnu/packages/geo.scm (qgis): Likewise.
* gnu/packages/password-utils.scm (qtpass): Likewise.
* gnu/packages/video.scm (openshot): Likewise.
* gnu/packages/web-browsers.scm (kristall): Likewise.