[TASK] Streamline accordeon triggers in Install Tool

The panel headers of the install tool have been
streamlined by making the fully clickable and adding
an indicator whether the panel is collapsed or not.

Change-Id: I8e05a647d2fd208c405b9467c48e59e674eec1fd
Resolves: #71383
Resolves: #71385
Releases: master
Reviewed-on: https://review.typo3.org/44628


Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>