Fix null-dereference in parseXMLMemberDynamicType (#5565)

* Refs #22535. Add regression test.

Signed-off-by: Miguel Company <[email protected]>

* Refs #22535. Fix issue.

Signed-off-by: Miguel Company <[email protected]>

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Signed-off-by: Miguel Company <[email protected]>
(cherry picked from commit c0e7929)

# Conflicts:
#	src/cpp/xmlparser/XMLDynamicParser.cpp
#	test/unittest/xmlparser/XMLParserTests.cpp

Author: MiguelCompany