Fix bug #67440: append_node of a DOMDocumentFragment does not reconcile namespaces

The test was amended from the original issue report. For the test:
Co-authored-by: php@deep-freeze.ca

Fix bug #67440: append_node of a DOMDocumentFragment does not reconcile namespaces

The test was amended from the original issue report. For the test:
Co-authored-by: php@deep-freeze.ca

The problem is that the regular dom_reconcile_ns() only works on a
single node. We actually have to reconciliate the whole tree in case a
fragment was added. This also required to move some code around such
that this special case could be handled separately.

Closes GH-11362.

show more ...