Attach generated_pr_notices into the PR description

[kbukum1]

What are you trying to accomplish?

Implementing a feature to attach generated PR notices into the PR description. This includes using log levels to match messages shown on the UI, ensuring clear communication of deprecation and other important information.

What issues does this affect or fix?

This PR adds the generated bundler v1 deprecation warning into alongside with other generated PR notices into PR description.

Anything you want to highlight for special attention from reviewers?

• This PR introduces a generic method to provide informational messages, warnings, and errors in the PR description. Currently, it is used to show bundler v1 deprecation warning in this PR but can also be used to show other kinds of information, warnings, and errors.

How will you know you've accomplished your goal?

• Demonstration: The deprecation alert and other generated PR notices should appear in the PR description as intended.

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.

[kbukum1]

The feature implemented in the following PR, #10421