runners refactoring to allow run embedded the test suite

Working on [MARMOTTA-508](https://issues.apache.org/jira/browse/MARMOTTA-508) @ja-fra and myself we had realized there were some things a bit dirty in the runners. This PR includes a general refactorization of some parts we think is a much cleaner separation of the test suite internal logic and some command-line things.

Before merging it into `master` we'd like to double check it with @sspeiche and @spadgett, specially to avoid lateral effect on the current work in the paging tests.