remove unnecessary use of OUString constructor in UNOTOOLS module

Change-Id: Iad166e6b9ce0877200bd58c388b3914b15167196
remove unnecessary use of OUString constructor in UCBHELPER module

Change-Id: I3e3cfc69c14a300f330264ae40c135e8135adb97
remove unnecessary use of OUString constructor in UCB module

Change-Id: Ic75e5aad03d66590e78275304c766c1c00179387
remove unnecessary use of OUString constructor in TOOLKIT module

Change-Id: I0cc8c507ede20d5db1942b75e0c4b660dcd66c97