[TASK] Provide .gitignore and ignore code coverage report folder

Releases: 6.1
Resolves: #47178
Change-Id: Ieaeaf4e0560bd8ff3dd64176bd55a7e91640bd7a
Reviewed-on: https://review.typo3.org/19888
Reviewed-by: Wouter Wolters
Reviewed-by: Stefan Neufeind
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn