Allow plugins to be loaded from scripts, not just compiled DLLs

**What do you want to see?**
Allow plugins to be loaded from scripts - ideally either C# or Python - in addition to from DLLs.

**How would it help players?**
Better transparency for mods, so players aren't left wondering what's in the mystery DLL. Give modders the option to just write scripts without having to compile them into DLLs if they don't want to install a C# compiler (or they want to use Python).

**Alternatives**
N/A

**Screenshots and mockups**
N/A

**Things to consider**
How to structure the plugins so they can be installed in the Plugins folder without being in DLLs but also without colliding with each other

**Related issues**
N/A