tdf#137652 add xmlscript unittest & infrastructure

entire module was not covered by unittests and there was no way
to test some of the latest fixes done there, like f4a5893ece.

Now it is possible and a test for
https://gerrit.libreoffice.org/c/core/+/104619 was added

Removed remains of older unused tests.

Change-Id: Ide7bc3704efa1bb4bc62ed71bf4dd8b1ad4e800f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112569
Tested-by: Thorsten Behrens <thorsten.behrens@allotropia.de>
Reviewed-by: Thorsten Behrens <thorsten.behrens@allotropia.de>

xmlscript/Module_xmlscript.mk

@@ -14,4 +14,8 @@ $(eval $(call gb_Module_add_targets,xmlscript,\
     Package_dtd \
 ))
 
+$(eval $(call gb_Module_add_check_targets,xmlscript,\
+    CppunitTest_xmlscript_cppunit \
+))
+
 # vim: set noet sw=4 ts=4: