which can use the more efficient *StringConcat
Also fix a crash in stringview plugin which
started happening while I working on this.
Change-Id: I91a5b9b7707d1594d27d80b73930f5afac8ae608
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/114568
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>