remove unnecessary use of OUString constructor in STOC module

Change-Id: I980223cedb6d0054ef71cbd81691f70a24f506ad
remove unnecessary use of OUString constructor in SHELL module

Change-Id: Ibdb750dc8e0f4cd0f186d5801c0a269edd939547
remove unnecessary use of OUString constructor in SFX2 module

Change-Id: Ieafc413136a9b4b907de034914d918212e4c16e3
remove unnecessary use of OUString constructor in SD module

Change-Id: Id3591b232b43deeb70e3e2fffb5c6a8f561223dd