CLI11 fix spaces

[galabovaa]

Closes #2385

CLI11 handles multiple files with

catch (const CLI::ExtrasError& e) 

and

catch (const CLI::ArgumentMismatch& e) 

in RunHighs.cpp, so checkSingle is not required in HighsRuntimeOptions.h

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.11%. Comparing base (0bfb4cc) to head (d96f16c).
Report is 6 commits behind head on latest.

Additional details and impacted files

@@            Coverage Diff             @@
##           latest    #2387      +/-   ##
==========================================
- Coverage   79.11%   79.11%   -0.01%     
==========================================
  Files         346      346              
  Lines       84952    84910      -42     
==========================================
- Hits        67212    67173      -39     
+ Misses      17740    17737       -3     

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[jajhall]

Beautiful!

I've checked it locally

I did wonder about having a test to verify that this facility isn't broken in future. I guess that we have some "command line" CI tests to which is could be added