Use UUIDs to identify types

[randomPoison]

Right now we use the user-provided names for Resources/Components to identify them when deserializing update data sent from the editor. While this is an okay solution in the short term, we'll need a more stable way of identifying types in order to support prefab editing in the future. To do this, we can use serde-dyn, which provides the trait TypeUuid.

TODO: Note that we'll have to define our own TypeUuid trait because of the orphan rule.

TODO: Note that we should put this behind a feature until we're ready to make it mandatory.