[#1002] Remove dependency from chevah.utils

Problem description
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reviewer @alibotean 

We want chevah.empirical to only depend on chevah.compat 

In this way it all code for testing "chevah.utils" package will be moved in chevah.utils.


Why we got into this (5 whys)
=============================

chevah.empirical came from chevah.commons which came from chevah.server ... so many code was mixed.


Changes description
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All chevah.utils imports were removed and code specific to chevah.utils package was removed.

The stuff here is pretty light. The removed code will be moved in chevah.utils in the #1002 branch from chevah.utils 


How to try and test the changes
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Nothing special here.