Add the "Configure Unit Tests" command.

[ericsnowcurrently]

(for #4286)

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
• Title summarizes what is changing
• Has a news entry file (remember to thank yourself!)
• Has sufficient logging.
• Has telemetry for enhancements.
• Unit tests & system/integration tests are added/updated
• Test plan is updated as appropriate
• [ ] package-lock.json has been regenerated by running npm install (if dependencies have changed)

[codecov]

Codecov Report

Merging #4303 into master will increase coverage by 23%.
The diff coverage is 55%.

@@           Coverage Diff            @@
##           master   #4303     +/-   ##
========================================
+ Coverage      57%     79%    +23%     
========================================
  Files         348     422     +74     
  Lines       14547   19354   +4807     
  Branches     2247    3111    +864     
========================================
+ Hits         8257   15256   +6999     
+ Misses       5761    4095   -1666     
+ Partials      529       3    -526

Flag	Coverage Δ
#Linux	68% <39%> (?)
#Windows	69% <39%> (?)
#macOS	68% <39%> (?)

[ericsnowcurrently]

triggering CI rebuild