Add validation/prevent --set-owner, --set-owner-short, and --set-ham …

[Crank-Git]

…from accepting empty or whitespace-only names. This is in relation to feature request meshtastic/firmware#6867.

Added test validation and when trying to set long, short, and ham names we get the following via the cli:

python -c "import sys; sys.argv = ['', '--set-ham', '   ']; from meshtastic.__main__ import main; main()"
ERROR: Ham ID cannot be empty or contain only whitespace characters

python -c "import sys; sys.argv = ['', '--set-owner', '   ']; from meshtastic.__main__ import main; main()"
ERROR: Long Name cannot be empty or contain only whitespace characters

python -c "import sys; sys.argv = ['', '--set-owner-short', '   ']; from meshtastic.__main__ import main; main()"
ERROR: Short Name cannot be empty or contain only whitespace characters

Please let me know if there is anything else that I should add or modify. I have no idea what I am doing with Android SDK/development, so I believe someone will need to add this validation so the app also gives an error/warning when trying to set these.

[codecov]

Codecov Report

Attention: Patch coverage is 65.71429% with 12 lines in your changes missing coverage. Please review.

Project coverage is 60.08%. Comparing base (622a435) to head (8a6ee5f).
Report is 13 commits behind head on master.

Files with missing lines	Patch %	Lines
meshtastic/__main__.py	61.29%	12 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #782      +/-   ##
==========================================
+ Coverage   59.60%   60.08%   +0.48%     
==========================================
  Files          24       24              
  Lines        4114     4149      +35     
==========================================
+ Hits         2452     2493      +41     
+ Misses       1662     1656       -6     

Flag	Coverage Δ
unittests	60.08% <65.71%> (+0.48%)	⬆️

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[ianmcorvidae]

Sorry for the delay on my getting back to this. Looks good, I'll merge it now, and probably push out a release soon as well.