Fix Libyear Parsing Function to Support More than One Dependency Manifest per Project

[IsaacMilarky]

Description

• Use .get instead of dictionary indices to avoid missing info in poetry.lock
• Make each dependency function extend the dep list instead of returning once we find the first manifest file
• Parse the path into a short string that can be more easily compared
• Parse through all found dependency manifest files and put them all in one big dictionary

Notes for Reviewers
I have tested locally on my repos but @sgoggins you might want to test it a bit on other repos.

Signed commits

• Yes, I signed my commits.

[sgoggins]

LGTM.