Refactoring integration test

[mbrandenburger]

Many integration tests currently have redundant configurations via topology.go. While redundant code is not always bad, some code, in particular, the registration of the views could be reused among those tests.

This will help to maintain the tests, simplify the topology and thereby highlight what actual differences between the different integration tests.

@adecaro do you think it would make sense here to refactor this topology so we can re-use the view configuration in multiple integration tests?

I would assume that most of the views we are attaching to alice, bob, and co are the same. This would allow us to highlight better the actual configuration change in this topo, namely, adding two TMSs ... Maybe this could be handled in a separate PR. WDYT?

Originally posted by @mbrandenburger in #476 (comment)

[adecaro]

Hi @mbrandenburger , do you mean to have a single topology for all the tests we run?