raise if given more than one result for the same parameter name

[jenshnielsen]

This would have prevented a bug identified in #3186 where multiple values for the same result was passed to add_result.

It turns out that a number of tests relied on being able to pass in multiple parameters with setpoints that had been pre expanded and therefore multiple values for any shared setpoints. Technically this is an api break and should therefor probably be documented as such. I do not expect that many users would pre expand the setpoints so I am not that concerned about it.

This also revealed that one of the tests were buggy since it explicitly passes the same parameters multiple times (due to some code being commented out)

@trevormorgan could you take a look

[codecov]

Codecov Report

Merging #3265 (f0fc25e) into master (2dc292b) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #3265   +/-   ##
=======================================
  Coverage   66.20%   66.20%           
=======================================
  Files         220      220           
  Lines       29246    29250    +4     
=======================================
+ Hits        19361    19365    +4     
  Misses       9885     9885           

[jenshnielsen]

@trevormorgan Ping

[trevormorgan]

@jenshnielsen changes look good to me.