Support Aliased Dependencies in NPM

[DarkaMaul]

At the moment, the support for NPM dependencies fails at aliased dependencies.

Example for angular package.json

    "@types/node": "^16.11.7",
    "@types/selenium-webdriver": "3.0.7",
    "@types/selenium-webdriver4": "npm:@types/[email protected]",
    "@types/semver": "^7.3.4",
    "@types/shelljs": "^0.8.6",

This PR tries to handle this case by :

• Adding an AliasedDependency class that inherits from Dependencies.
• Installing dependencies from the real source instead of the alias name

[woodruffw]

Reviewed this for overall structure, and LGTM! The pip-audit CI will be fixed with #84, so we can merge here without that.

CC @ESultanik for a review as well -- I think you know it-depends much better than I do 🙂