fast immergancy fix : use GetExportedTypes()

[kianzarrin]

Use GetExportedTypes() instead of GetTypes()

Reasons:

• The game does useGetExportedTypes() every time it loads an assembly so using GetExportedTypes() is harmless
• calling GetTypes() makes NExt2 incompatible with mods that have direct references to other mods (not only harmony)
• avoiding direct references in private types is hard because sometimes the compiler creates hidden private types.

[kianzarrin]

@andreharv I will now fork NExt2 and do this. should I create a PR? do you need the dll as well?