Add a simple way to launch pgtop

[alexgarel]

It's very handy to be able to use pgtop even on a production database to see what's going on.

Add a simple way to launch pgtop.

[alexgarel]

It can be a make pgtop target.

To launch it it can be a docker/tools.yaml docker file with tools to launch manually (it should be used along with base docker files defined in COMPOSE_FILE variable). (prefered one)

or a pgtop docker container in the right network and pointing at the right address.

[alexgarel]

An even simpler way is to publish docker ports so that it is accessible on localhost @john-gom, I did it in prod (with a small edit directly in prod), to let @cquest analyze requests.