Get rid of DECLARE_STL_SET

Change-Id: Ie3e2fb6d9376e3b6e98bb17671b3e9e93cd69923
Get rid of DECLARE_STL_STDKEY_SET

Change-Id: I4817694d183d525fa5a29eb9693a20d491549e5d
Get rid of comphelper::UStringLess

...default std::less<OUString> is just fine.

Change-Id: Ib9d3c10f2817d757f3c19eb3d4607095883af91a