Map sucks

Background for body and secondary boxes

Scaffold edit settings feature in super user; re-arrange appConfig class

The API will send the appConfig as key value pairing, so we need some transform procedures. The getAppConfig function prepares for super user setting edit.

Move warning from card-header to alert tag; remove workaround via customTexts (system_announcement)

Application data on impressum page only

Logo flexible; move some main.dataservice infos into appConfig; new appConfig data: html, warning etc.

by giving systemAnnouncement a starting value

resolves https://github.com/iqb-berlin/testcenter-frontend/issues/247

closes https://github.com/iqb-berlin/testcenter-frontend/issues/282

restores the version of notifyDyingTest with employs the specialized endpoint and the fetch-api als alternative to sendBeacon. It was appareantly lost my merging with master.

No Changes in the behaviour.

resolves https://github.com/iqb-berlin/testcenter-frontend/issues/247

Why? Consider the following scenario before this change: we have 10 test-sessions prepared but 7 testees are present. The autoCheckAll-mode is on. We click pause and `pause` is sent to all ten test-sessions. The seven session which are online go in the pause mode and the controller sends back the state `{CONTROLLER: paused}`. Now we hit `resume` - and reach the only seven test-sessions which are in pause now. Now one of the the remaining three testees shows up and starts his session. Ge gets the pending pause from before command but no resume. Now he is paused, while the rest isn't.

To avoid this case of inconsistency we send the resume command to all test-sessions anyway.

Another approach would hve been to drop the command-"caching" for pending tests. But this would have other impacts in scenarios where testees who start later.

changes the selection/check behaviour so, that after a block is selected (the first time) the checked sessions are kept and the clicked one is added if not there

makes the toggle between all-of-type and only-this-row selection ( = spreading) only happen when clicked on the very same session

changes back the the click-selection-order: first click on a block selects the test only, seconds selects all tests of the same species.

Why? To select all at first was an idea to make it easier for popele who don't understand that they have to select tests. But those are covered by the selectAll-Testmode now. So we can return to the previous behaviour which we consider to be more intuitive.

In the frist implementation of the group-monitor the test-sessions replaced a combination of person and test so they needed there own id. Now, they represent only tests and we don't show a person which is a logged in but has not started a test right now anymore, we don'T need the combined id anymore as well.