Enhancement: Fixes in the reference configuration for ScienceMesh

Following the successful onboarding of CESNET, this PR brings some
improvements and fixes to the reference configuration, as well as
some adaptation to the itegration tests.

https://github.com/cs3org/reva/pull/4186
https://github.com/cs3org/reva/pull/4184
https://github.com/cs3org/reva/pull/4183
