Optional blocking in Keithley 2450

[aaronsharpe]

Added a parameter to control whether or not ramp commands sent to Keithley 2450s block<!--

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[jenshnielsen]

Create a file in the docs\changes\newsfragments folder with a short description of the change.

Could you create a file called improved_driver.5547 as noted here with a description of the fix?

[codecov]

Codecov Report

Merging #5547 (eb439f8) into main (faa0790) will decrease coverage by 0.01%.
Report is 29 commits behind head on main.
The diff coverage is 50.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5547      +/-   ##
==========================================
- Coverage   66.32%   66.32%   -0.01%     
==========================================
  Files         354      354              
  Lines       30953    30958       +5     
==========================================
+ Hits        20530    20532       +2     
- Misses      10423    10426       +3     

[aaronsharpe]

Added the requested changes. Sorry for missing the newsfragments doc!