Stucts can be autocompleted when extended types disabled.
Created two functions to make the code brighter. They extract the methods/fields from an XIdlClass and return them in a std::vector<OUString>.
I had to modify file basic/source/comp/dim.cxx, to check on UNO types when code completition is on.
Change-Id: Id93a6fe896424efb7868f6102985f59fb419b17e