feat: Generate correct From impls on type changes

Author: Techassi

crates/stackable-versioned-macros/src/codegen/vstruct/field.rs

@@ -202,6 +202,25 @@ impl VersionedField {
                     ) => quote! {
                         #ident: #default_fn(),
                     },
+                    (
+                        _,
+                        ItemStatus::Change {
+                            from_ident: old_field_ident,
+                            to_ident,
+                            from_type,
+                            to_type,
+                        },
+                    ) => {
+                        if from_type == to_type {
+                            quote! {
+                                #to_ident: #from_ident.#old_field_ident,
+                            }
+                        } else {
+                            quote! {
+                                #to_ident: #from_ident.#old_field_ident.into(),
+                            }
+                        }
+                    }
                     (old, next) => {
                         let old_field_ident = old
                             .get_ident()

crates/stackable-versioned-macros/tests/good/basic.rs

@@ -9,8 +9,7 @@ use stackable_versioned_macros::versioned;
     version(name = "v1beta1"),
     version(name = "v1"),
     version(name = "v2"),
-    version(name = "v3"),
-    options(skip(from))
+    version(name = "v3")
 )]
 pub(crate) struct Foo {
     #[versioned(