Fields

[HurricanKai]

This adds (struct) fields in both the symbol and emission layers. This does not include logic to include fields in a struct, it purely represents fields as symbols and is able to emit them into C# as root symbols

[HurricanKai]

I am a bit unhappy about the field types. They right now just accept a TypeSymbol which is kind of wrong, since the name given there should be able to both represent an inbuild type (int) and externally defined type (System.String) and a type which has been emitted previously (-> these could be treated as "externally defined")
Right now all these goals can still be met, but it's kind of unclean (new StructSymbol(new IdentifierSymbol("int")), new StructSymbol(new IdentifierSymbol("string"))).
Note that the type given to fields can not just be a string / identifier because this should also carry whether the type is a reference or value type (and other type-related info. Maybe we should just have ExternalTypeReference?) (-> using these references we could even build the dependency tree?)

[Perksey]

my dogs on my lap so i'll just assume this is fine