Add bun ecosystem FileParser

[markhallen]

What are you trying to accomplish?

This PR is the next step towards using bun in it's own ecosystem.

Follows #11445, #11446, and #11508

Anything you want to highlight for special attention from reviewers?

We have ignored some opportunities for refactoring as this is mostly moving code from npm_and_yarn to the new javascript parent folder and reorganizing. The new folder structure should allow for future refactoring.

How will you know you've accomplished your goal?

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.