request: suggested fix action to make a new type

If you have

mod some_name;

then when the file for the some_name module doesn't exist, a suggested action will be to create the file.

Currently, this doesn't happen with types.

If you have code like

struct Ast {
  pub items: Vec<Item>
}

and assuming there's no Item type in scope, there won't be a suggested fix to make the Item type. There's suggestions for new methods, getter/setter, deref impl, but no suggested fix to "make a new struct with this name because it doesn't exist".

The issue names no repository files or tests. Start by locating the existing suggested action for missing module files and compare it with the current actions for unresolved types. Add coverage for offering a new-struct action for an unresolved Item reference, then verify the example produces that suggestion.