Move the class out of weld.hxx into its own header, in order to make it easier to keep an overview and to avoid having to recompile ~all UI code when the class is modified. Change-Id: I5b23b02151c75bb49831a2bbf8d515eb0b54415e Reviewed-on: https://gerrit.libreoffice.org/c/core/+/199068 Reviewed-by: Michael Weghorn <m.weghorn@posteo.de> Tested-by: Jenkins