Refactor open ephys

[h-mayorquin]

This came up when trying to fix a problem with a missing probe channel in open ephys. While I was trying to understand how the function reads the contact ids I thought that I could do a small improvement on the variable names by extracting some dictionary variables that are accessed many times on the loop.

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 89.44%. Comparing base (5e96807) to head (bc1b6c0). :warning: Report is 162 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #305      +/-   ##
==========================================
+ Coverage   89.38%   89.44%   +0.05%     
==========================================
  Files          10       10              
  Lines        1885     1895      +10     
==========================================
+ Hits         1685     1695      +10     
  Misses        200      200              

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[alejoe91]

Closing in favor of #339