test: add tests for app_runmacro.py

[ycexiao]

What problem does this PR address?

Closes #8.

Add more tests for app_runmacro.py, especially about the processors for the commands.

What should the reviewer(s) do?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.94%. Comparing base (c0de591) to head (2ee580e).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main       #9      +/-   ##
==========================================
+ Coverage   92.46%   92.94%   +0.48%     
==========================================
  Files           4        4              
  Lines         146      156      +10     
==========================================
+ Hits          135      145      +10     
  Misses         11       11              

Files with missing lines	Coverage Δ
tests/test_runmacro.py	100.00% <100.00%> (ø)

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[ycexiao]

@sbillinge, it's ready for review.