[#1852] Move brink variables out of py script into a dedicated file.


Problem description
===================

The pavement.py Python file contain some variables which are used in paver.sh script.
This was there since we used a shared paver.sh script.

Now that we have an independent paver.sh script we should move them out of python script.


Changes description
===================

paver specific configuration were moved into a dedicated configuration file.

The main reason for moving the variables in a dedicated configuration file was to support 'skip' value for brink repo... and use a specific value for all other repos.


How to try and test the changes
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reviewers @alibotean @dumol 

Check that changes make sense.

Thanks!