Vector input to config file

[phlptp]

From #1067, there is a bit of ambiguity in the handling of config file with vector input and multiple consecutive parameters. For example

option1=[3,4,5]
option1=[4,5,6]

Currently this is handled as if it were

option1=[3,4,5,4,5,6]

But this could be confusing in the case where the input was referring to a vector of vectors.
This PR adds a separator in the sequence to separate the vector so they are two vectors of 3 elements each.
Will need to verify if this change has other side effects. It is a pretty unusual situation.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (e4ee3af) to head (dcebf0d).
Report is 37 commits behind head on main.

Additional details and impacted files

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##              main     #1069    +/-   ##
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  Coverage   100.00%   100.00%            
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  Files           17        17            
  Lines         4546      4627    +81     
  Branches         0       993   +993     
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+ Hits          4546      4627    +81     

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[phlptp]

@henryiii I will merge this Tuesday, unless you have some issues with it.

[pauldmccarthy]

@phlptp This appears to have resolved the issue, thanks very much for looking into it!

edit my comment was a bit premature, as I am still getting inconsistent behaviour when I adjust my example a little bit - will continue the discussion at #1067