Add arguments to integration script

What does this MR do and why?

This is another improvement for spec/scripts/integration.sh. This time we're adding arguments to it so that you can test other changes with it. For example, instead of this convoluted test plan we could have just executed

./spec/scripts/integration.sh \
--set webserver.goGc.enabled=true \ 
--set webserver.goGc.value=55 \
--set indexer.goGc.enabled=true \
--set indexer.goGc.value=75

Screenshots or screen recordings

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.