feat: --jsonlog prints messages as JSON

[rix0rrr]

TODO:

• Errors?
• Flag name?
• Stack activity printer?

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 62.96296% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.08%. Comparing base (0900f26) to head (b7a355c).

Files with missing lines	Patch %	Lines
packages/aws-cdk/lib/cli/io-host/cli-io-host.ts	60.00%	10 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1459      +/-   ##
==========================================
- Coverage   88.13%   88.08%   -0.05%     
==========================================
  Files          74       74              
  Lines       10595    10620      +25     
  Branches     1454     1458       +4     
==========================================
+ Hits         9338     9355      +17     
- Misses       1229     1237       +8     
  Partials       28       28              

Flag	Coverage Δ
suite.unit	88.08% <62.96%> (-0.05%)	⬇️

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