Robust ovm prod tests

[i-stam]

This PR refactors and extends the SynthExchange ovm prod tests to make them more robust:

• Modular, "behaviour" based implementation.
• No assumption about the value of the waiting period.

[codecov]

Codecov Report

Merging #1130 (3c4a024) into develop (468a28b) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #1130   +/-   ##
========================================
  Coverage    95.62%   95.62%           
========================================
  Files           76       76           
  Lines         5413     5413           
  Branches       661      661           
========================================
  Hits          5176     5176           
  Misses         237      237           

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