Add option to show MD5 checksums in dvc ls

[petebachant]

This feature would be useful for a project I'm working on that uses DVC as a dependency.

• ❗ I have followed the Contributing to DVC checklist.
• 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.

[codecov]

Codecov Report

Attention: Patch coverage is 25.00000% with 15 lines in your changes missing coverage. Please review.

Project coverage is 90.78%. Comparing base (f56343d) to head (9d56acc).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
dvc/commands/ls/__init__.py	21.05%	14 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10573      +/-   ##
==========================================
+ Coverage   90.61%   90.78%   +0.16%     
==========================================
  Files         504      504              
  Lines       39582    39593      +11     
  Branches     5716     5721       +5     
==========================================
+ Hits        35868    35945      +77     
+ Misses       3032     2982      -50     
+ Partials      682      666      -16     

Flag	Coverage Δ
	90.73% <25.00%> (?)

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