A basic acceptance tests clicking through installer
using a mysql db connection, checking backend login
and "blank" site frontend output works.

Change-Id: Ie14d9c6fd8280d382b4041f98fa04ed00ef8386c
Resolves: #81285
Releases: master, 8.7
Reviewed-on: https://review.typo3.org/52880


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Claus Due <claus@phpmind.net>