0027241: Create a complete test case to verify reading of all attribute types from...

0027241: Create a complete test case to verify reading of all attribute types from MDTV-Standard document

Add test case that works in one of two modes:
1) create synthetic document (in old version of OCCT) containing all possible attributes.
2) open the document and compare all attributes with expected values.

Fixed reading of TDataStd_NamedData attribute and PColStd_HArray2OfReal.
Point and curve representations are created even from NULL geometry handles.
The code is simplified by abandoning usage of templates from StdObjMgt_ContentTypes class for persistent data elements.

Fixed SetAsciiString Draw command failed when the target label contained NamedData attribute.