Use the same object when checking if the user is blocked instead of creating a new...

Use the same object when checking if the user is blocked instead of creating a new one.

* Block::parseTarget() first called trim() on its parameter which was converting objects into string, thus making the checks for object and null useless; now trim() is called after these checks.
* User::getBlockedStatus() was passing $this->getName() to Block::newFromTargert() which in turn was passed to Block::parseTarget() where a new User object was created.
  Instead of this, the User object is directly passed to Block::newFromTargert(), which avoids creating a new object for the same user.

Change-Id: Iffea21d4f53e8692072749264f7486c22b6be5fd