makes the testController only connect to commands-stream if the testMode has the new capabillity `isMonitorable`

fixes a bug which made tests in modes without saveReponses to write back some data when test with saveReponses was opened before.

Explanation: The testmode comes later with getTestData and is set correctly in the RUNNING stage, while in LOADING stage it war still the testmode of the test before! So if we opened a test in TRIAL mode after running a test in HOT mode, the loading stage will be write back to backend. As a workaround, we reset to DEMO here, so while in loading stage `saveResponses` is always false.

As all tests of one login are always in the same mode, maybe it would be better to retrieve the testmode from the login instead by getTestData.

extends filterSessions ba the capability of filtering by superState and bookletSpecies and adds unit tests.

most of them occured because of missing dependencies in the testingModule, some where console-outputs from backends.services (which are mocked now)

which does not make anymore sense, since we can only only jump to top-level testletes ( = blocks).

At the time the stats for checked sessions where updated, the main sessions object was not updated, so the number of checked sessions where compared with the number of sessions during the last change. At the first time the previous number was always null.

radically simplifies the getCurrent function and it's test to get rid of a bug, which was, that subsequent non-block units where counted to the unit count of the last block

extends the alert component to subscribe to an customtext-key alternatively to a plain text and switch between both "modes"

...because that does not make much sense at all in auto-check-all mode. sessions get filtered before sending control anyway.

(what could happened when a filter was activated for example!)