[new pluggin] - bandwhich

### Is your feature request related to a problem? Please describe

'm always frustrated when I need to monitor network bandwidth usage per process on my system. While there are various tools available, they often lack the simplicity and efficiency provided by bandwhich.

### Describe the proposed solution

I would like to see an official asdf plugin for bandwhich, a command-line utility for displaying current network utilization by process, connection, and remote IP/hostname. This plugin would allow users to easily install and manage different versions of bandwhich through the asdf version manager.

### Describe similar `asdf` features and why they are not sufficient

Currently, asdf does not have a plugin for monitoring network bandwidth usage per process. Existing plugins in asdf focus on other functionalities such as programming languages, databases, and other utilities but none provide the specific functionality that bandwhich offers.

### Describe other workarounds you've considered

Other solutions involve manually downloading and installing bandwhich, or using alternative tools that do not integrate well with the asdf version management system. These alternatives lack the ease of use and version control that an asdf plugin would provide.

The issue requests an official asdf plugin for bandwhich, but names no repository files, tests, or entry points. Start by reviewing the asdf plugin conventions and existing utility plugins; done means users can install and manage bandwhich versions through asdf.

Written by the indexing model from the issue text.