Fixes: NB#242340 - VKB; Input Chinese characters become invalid string after backspace with English VKB.
Fixes: NB#242340 - VKB; Input Chinese characters become invalid string after backspace with English VKB.

RevBy: Pekka Vuorela
Details: Word boundary for determining preedit after backspace press is now searched
         with QTextBoundaryFinder instead of regular expression which was used previously.
         The fix is not perfect since one chinese letter still gets selected as preedit
         after every other backspace. Fixing even that would require knowledge of which
         letters are acceptable in each language.

KDE/plasma-maliit-plugins,KDE/plasma-maliit-plugins,KDE/plasma-maliit-plugins,RHawkeyed/plugins,maliit/plugins,maliit/plugins,develersrl/maliit-demo-qml,develersrl/maliit-demo-qml,RHawkeyed/plugins,RHawkeyed/plugins,maliit/plugins,develersrl/maliit-demo-qml,KDE/plasma-maliit-plugins,RHawkeyed/plugins,develersrl/maliit-demo-qml,maliit/plugins,RHawkeyed/plugins