(Feature Request) Unreal: Listing or iterating through all fields In a UObject

Nobody has claimed this yet.

While working on the THPS 1+2/3+4 autosplitter, when starting to adopt UObject field names to find offsets (and more directly, #112), but found it difficult to actually figure out what I was looking for. It was useful to modify the asr crate to list all fields in a given UObject for me.

For example, to UObject, I added the following:
```
pub fn list_fields(&self, process: &Process, module: &Module) {
let name = self.get_fname::(process, module).unwrap().validate_utf8().unwrap().to_string();
crate::print_message(&format!("Fields for UObject {}:", name));

self.get_uclass(process, module)
.unwrap()
.list_fields(process, module);

crate::print_message(&format!(""));
}
```

and to UClass,
```
fn list_fields(
&self,
process: &Process,
module: &Module,
) {
for field in self.properties(process, module) {
let name = field.get_fname::(process, module).unwrap().validate_utf8().unwrap().to_string();
let offset = field.get_offset(process, module).unwrap();

crate::print_message(&format!("{}: offset {:#018x}", name, offset));
}
}
```

Obviously this solution isn't great as it relies upon alloc. I think the ideal solution is to expose the iterator and allow the user to do anything for each entry. I don't really have the time to iterate upon it right now to make a proper pull request so I'm making this issue to present the idea.

Start with the UObject and UClass list_fields examples in the issue, then trace UClass::properties and the field name and offset accessors. Done means exposing iteration over a UObject's fields without requiring alloc, while allowing callers to perform their own action for each entry.

Written by the indexing model from the issue text.