Add lowest_prerelease_suffix method

[amazimbe]

What are you trying to accomplish?

I need to be able to get the correct lowest prerelease suffix for a version. I can then use this to build the correct version ignore ranges in dependabot core as well as dependabot API.

Currently, we have this suffix hardcoded in a few areas of the core codebase and api codebase . Unfortunately, this suffix is ecosystem-specific and that's why this PR adds a method to return the correct suffix in a specific ecosystem.

Once this PR get's merged I can then fix this issue. There is already a draft PR for that here

Anything you want to highlight for special attention from reviewers?

It is a bit cleaner rather than checking class names. For example:

suffix = "a0" if version.is_a? Dependabot::Maven::Version

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.