Added more tests to test_horizontal_portscans.py

[Sekhar-Kumar-Dash]

Fixes Issue #511

Changes proposed

With this pull request, I have added more tests to test_horizontal_portscans.py, which will improve the code coverage

Check List

• My code follows the code style of this project.
• My change requires changes to the documentation.
• I have updated the documentation accordingly.
• All new and existing tests passed.
• This PR does not contain plagiarized content.
• The title of my pull request is a short description of the requested changes.

[AlyaGomaa]

Hello @Sekhar-Kumar-Dash Very nice work you've done there, thank you!
Once the checks pass i will merge it.

However i have one small comment, i saw many duplicate functions in your PR, i recommend you check those before your future PRs
Usually i don't check them manually, they are displayed as warnings in IDEs like pycharm so you can check that before committing, and i believe we have it as a pre-commit hook so in the future commits will be automatically rejected until that's fixed.

Thanks for the hard work! Keep it up.

[Sekhar-Kumar-Dash]

Hi @AlyaGomaa Thank you so much for reviewing my PR and for making the corrections. Sorry for the duplicate functions, I will check that out

[AlyaGomaa]

You're welcome!:)