[Qualify of Life] Rewrite the debug server to make use of structopt instead

[Raytwo]

QoL suggestion

Is your suggestion related to a usage problem? Please explain.

The debug server and its client use a custom made argument parser for the moment, and discrepancies can happen because of it, as you need to maintain all of it manually without a simpler system to do the heavy lifting.

How could we make this better?

Make use of the structopt crate to make the code more readable and simpler to maintain, and provide a good CLI interface

Is there an alternative way of doing things you'd like to suggest?

Using another crate, I suppose? Don't really know of a better one though.

Additional information

Related to arcropolis-server

[Raytwo]

Duplicate of #141