TMDM-7558: "Reading a XML record using SAX misses values when XML contains empty elements"

Fix incorrect SAX parsing in case of empty elements.
Adds unit test for issue.
(https://jira.talendforge.org/browse/TMDM-7558)

(cherry picked from commit fa8bd9a46b7ba5fe381e16ba3daa1630186f9443)
(cherry picked from commit c52bf8bcdc7a23ad19dd8cbc57a10f9b9db3469b)