Python 3 Upgrade + Yaml Based Modules + Yaml Language Lib + Functionality Enhancements

[Ali-Razmjoo]

@aman566 @itsdivyanshjain please continue work on this PR.

for tasks follow https://github.com/OWASP/Nettacker/projects/2

Checklist

• I have followed the Contributor Guidelines.
• The code has been thoroughly tested in my local development environment with flake8 and pylint.
• The code is both Python 3 compatible.
• The code follows the PEP8 styling guidelines with 4 spaces indentation.
• This Pull Request relates to only one issue or only one feature
• I have referenced the corresponding issue number in my commit message
• I have added the relevant documentation.
• My branch is up-to-date with the Upstream master branch.

Changes proposed in this pull request

Your development environment

• OS: x
• OS Version: x
• Python Version: x

[Ali-Razmjoo]

This PR is big enough already. So hold your breath and cross your fingers and let's go live and fix issues reported by users.