Fix StmtContext.findSubstatementArgument()/hasSubstatement()
When we are searching for a substatement we should also mind that
it can have its effective statement built. If we do not, we can end
up picking a statement which has been disabled by deviate.
Change-Id: I27743b5acbb2f617497d329423b239f363c54258
JIRA: YANGTOOLS-1157
Signed-off-by: miroslav.kovac <miroslav.kovac@pantheon.tech>
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit
b049955b52bcdf654e7b27530105745b0ca77ac0)