feat: Nextjs app router file Structure, Duplicate child handled & Import Aliases handled

[Katalogo]

First time contributor, help me contribute and Guide me

Linked issue/ticket

https://github.com/oslabs-beta/ReacTree/issues/40#issue-1778807874

Description

1. feat: Nextjs app router file Structure with 'src' Directory and without 'src' Directory handled
2. feat: Duplicate child handled
3. feat: Import Aliases like ( "paths": {"@/*": ["./src/*"]} or "paths": {"@/*": ["./*"]} ) both handled

Reproduction steps

Checklist

• [x] I've tried to follow the Contributing guidelines
• [x] I've titled my PR according to the Conventional Commits spec
• [ ] I've added tests that fail without this PR but pass with it
• [ ] I've linted, tested, and commented my code
• [ ] I've updated documentation (if appropriate)