Use ApiPath in YangInstanceIdentifierDeserializer
We are performing URL parsing in ApiPath, hence we can skip doing the
same thing in YangInstanceIdentifierDeserializer. This also improves
error reporting, as we provide additional info when we encounter parsing
errors. Error messages are also differentiated between parse errors and
semantic binding errors.
Escaping test has also updated, as ApiPathParser is intelligent enough
to understand both : and %3A in identityref name.
JIRA: NETCONF-631
Change-Id: I5fdb438d656b79199ea4bf316183d37280261eff
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>