entitlement: update BlockingStateDao methods with BlockingStateType info

Add BlockingStateType in the signature of BlockingStateDao methods
to get rid of guesses in ProxyBlockingStateDao.

This also simplifies the BlockingInternalApi API by removing
unnecessary methods (unused or only used in tests).

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
Merge branch 'entitlement-bug-fixes' of github.com:killbill/killbill into entitlement-bug-fixes