Add a plugin system

[PaulDotSH]

Hi, instead of having the features "built in", make a plugin system like other rats do, then we can write code for plugins easily without learning the how whole project works

[PaulDotSH]

A rat that uses a plugin system is async rat (https://github.com/NYAN-x-CAT/AsyncRAT-C-Sharp) if you want inspiration

[tiagorlampert]

Hello @Paulirl,
Thanks for your idea, sounds really interesting.

I'll take a look and think on some way to implement this. =D