kwineffects: Move infiniteRegion() to kwinglobals.h
infiniteRegion() is useful not only to effects but also other kwin components, so move it to kwinglobals.h in order to make backends stop depending on libkwineffects
infiniteRegion() is useful not only to effects but also other kwin components, so move it to kwinglobals.h in order to make backends stop depending on libkwineffects