Killport v1

[jkfran]

This PR introduces significant enhancements to the killport command-line tool. It adds new features such as mode-specific operations and expanded signal handling capabilities, along with the introduction of verbosity controls and a dry-run option. These changes aim to increase the flexibility and usability of killport for developers and system administrators who manage processes and containers via port assignments.

Key Features Added:

• Mode Selection: Users can now specify whether to target processes, containers, or both. This is controlled via the -m/--mode option. (Stop docker containers #6 )
• Signal Specification: The tool now supports specifying many different signals to be sent to processes or containers, enhancing the control users have over how they terminate these entities.
• Dry Run Option: This new feature allows users to simulate termination commands to see which processes or containers would be affected without actually performing the kill operation. (A mode that just prints out what's listening? #26 )
• Release as a library #29

Current Limitations:

• Platform Support: The enhancements are currently available only for macOS. Support for Linux is under development and will be released soon. Windows support is planned and will be addressed in a separate PR to ensure stability and compatibility across different system configurations.

Upcoming Updates:

• Linux Compatibility: We are working diligently to bring these new features to Linux. This will allow a broader user base to benefit from the updates.
• Windows Support: Windows compatibility is in the planning stage, and we aim to release it as a dedicated update to ensure that the tool meets the specific needs and configurations of Windows users.