feat(cdk): cdk diff --quiet suppresses progress messages

[MatasNed]

Hello maintainers

This is my first PR, so all feedback is welcome. This change adds support for the --quiet flag within cdk diff command, for users that would not like the following messages 'Stack ' and 'There were no differences' to be silenced for stacks which do not have any identified differences. The request was made by @nomike in the #26526, I simply followed the very well detailed description.

The change follows similar structure to existing command and how they are passed, I have also added to the README as per the contributing guidelines.

Before submitting I have.

• Built the packages & linted them
• Ran unit tests for the entire module
• Ran all integration tests in the suite from @aws-cdk-testing/cli-integ/bin/run-suite -a cli-integ-tests
• E2E tested by launching my small stack in account and executing diffs on it from my build.

Closes #26526

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[aws-cdk-automation]

The pull request linter has failed. See the aws-cdk-automation comment below for failure reasons. If you believe this pull request should receive an exemption, please comment and provide a justification.

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[MatasNed]

Clarification Request the aws-cdk CLI does not seem to mention or run snapshot tests as the configuration of the tests are different for the CLI. Reference to README

[rix0rrr]

Thanks for this! Looks well-done!

✅ Updated pull request passes all PRLinter validations. Dismissing previous PRLinter review.

[mergify]

Thank you for contributing! Your pull request will be updated from main and then merged automatically (do not update manually, and be sure to allow changes to be pushed to your fork).

[aws-cdk-automation]

AWS CodeBuild CI Report

• CodeBuild project: AutoBuildv2Project1C6BFA3F-wQm2hXv2jqQv
• Commit ID: df75727
• Result: SUCCEEDED
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[mergify]

Thank you for contributing! Your pull request will be updated from main and then merged automatically (do not update manually, and be sure to allow changes to be pushed to your fork).