0027454: Application hangs while opening a non-OCAF XML file

0027454: Application hangs while opening a non-OCAF XML file

1) Add protection against accessing null pointer in PCDM_ReadWriter::FileFormat.

2) In LDOM_XmlReader::ReadRecord, take into account that the character '>' can have no special meaning (e.g., in a text), and we must read the data behind this character to complete the current tag reading. This treatment concerns the mode of work when myTagPerStep is true.

3) Create a test case of reading of XML file not related to OCAF document.