port scanner issue solve

[tanujbordikar]

Description

In this PR, I have used a thread pool instead of creating threads for each worker and also has Limit the number of simultaneous connections to avoid overwhelming the network.

Fixes #455

Replace issue_no with the issue number which is fixed in this PR

Have you read the Contributing Guidelines on Pull Requests?

• [x] Yes
• [ ] No

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update
• [ ] Documentation Update

Checklist:

• [x] My code follows the style guidelines(Clean Code) of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I've edited the SCRIPTS.md and link to my code.
• [x] I have created a helpful and easy to understand README.md
• [x] My documentation follows Template for README.md
• [x] My changes generate no new warnings
• [ ] I have added tests/screenshots(if any) that prove my fix is effective or that my feature works.

[tanujbordikar]

Hey @avinashkranjan , I request you to please add a label of GSSOC'23 in this.PR.

[tanujbordikar]

hey @avinashkranjan, can you please add this PR's label.

[tanujbordikar]

hey @avinashkranjan ? please add a label!