Fix DefaultMapBodyOrder body sorting
NormalizedNodeContainer allows a MapEntryNode to return its children in
any order. That means we can very much trigger a case when body ordering
does not match expectations.
Improve test coverage to 100%, fixing the accidental UOE path as well as
improving reported messages.
JIRA: NETCONF-1325
Change-Id: Ieb6942105521928744466ec8573ca3839cb970c3
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit
85b4ce8affff70d8b8a31b78183f424eddf24790)