Adjust tests

[DanielSiepmann]

Currently the functional tests test the whole test. We should break them into two parts. One is the domain, the other the connection.

So the indexer, hook, etc. will be tested while the connection is mocked and we test that it will receive the right stuff.

The other part is the connection itself. We will call it with given arguments and test whether elasticsearch will deliver the documents. Each connection will get their own tests in the future.

Also the unit tests about hook doesn't guarantee what they should. We should mock the core datahandler and trigger the hooks, so we will test the interface and whether TYPO3 has changed something.