fix(codegen): Adds codegen for embedded objects and timer fields (#686)

* Adds code genning for embedded objects. See `AquariumState` as an example.
* Adds code genning for fields that are `Timer`. See `Aquarium` as an example.
* Codegens aquariums
* Fixes missing option for most primitive field types.

Projects/SerializationGenerator/SerializableMigration/ISerializableMigrationRule.cs

@@ -28,6 +28,7 @@ namespace SerializableMigration
             ISymbol symbol,
             ImmutableArray<AttributeData> attributes,
             ImmutableArray<INamedTypeSymbol> serializableTypes,
+            ImmutableArray<INamedTypeSymbol> embeddedSerializableTypes,
             ISymbol? parentSymbol,
             out string[] ruleArguments
         );