[TOOLS][PHPStan][TESTS][Docker] Rework testing Docker container into a more generic tooling container. Keep services up and run coverage and phpstan as commands, for performance and ease of use

docker/tooling/coverage.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+cd /var/www/social || exit 1
+
+yes yes | php bin/console doctrine:fixtures:load || exit 1
+
+runuser -u www-data -- vendor/bin/simple-phpunit -vvv --coverage-html .test_coverage_report