added support for alias @ <vcs_url> syntax

[Glizzus]

This PR aims to add support for the alias @ syntax requested by

Example:

h11 @ git+https://github.com/python-hyper/h11.git@master (from uvicorn)

Changes

• Updated the regex to capture optional alias in VCS URLs.
• Modified the parsing logic to handle and store alias.
• Added tests for alias syntax in VCS URLs.

Related Issues

Implements #74

[Glizzus]

All tests pass locally

[madpah]

@Glizzus - are you able to rebase from main please? Added a fix to CI which was failing due to a GitHub change. 🙇‍♂️