Inject the file_parser and use its attributes, Add a prepare! hook

[brrygrdn]

What are you trying to accomplish?

This PR makes a slight adjustment to the DependencyGrapher component to have it accept the file parser directly and execute it via a hook that ecosystems can redefine in the event they need to add before/after logic or an alternative parsing strategy in rare cases.

Since the FileParser's attributes contains the dependency files, credentials, etc, they can provide the grapher everything it needs to use native helpers to make additional calls without having to change the interface in future.

Anything you want to highlight for special attention from reviewers?

Rather than get into metaprogramming to instantiate the parser within the grapher, I elected for a simple DI approach to give us the prepare! method as a call site ecosystems can override in whatever way they need to.

This fulfils the goal of the grapher being the component which holds unto any logic that is redundant to parsing in update job cases without adding a lot of complexity - in the worst case scenario where an ecosystem needs a totally different parsing strategy for graphing, we can easily use the attributes of the base parser to create a new special-case one on the fly.

How will you know you've accomplished your goal?

Nothing breaks, this is a small structural refactor with no behaviour changes.

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.

[Ahmed3lmallah]

LGTM, with a minor comment.

[Ahmed3lmallah]

Thank you for addressing the comment!