Contentpacks don't include LookupTables for EventDefinitions

If an `EventDefinition` which uses lookup tables to set event fields is exported as a content pack, the referenced
lookup table is not included.
While this is a missing feature, implementing this has some difficulties.
lookup tables are referenced by name, while content packs work with ids only.
Converting the name to the ID cannot be done in `resolveNativeEntity` within AutoValue classes.
It would likely be better to refactor as much of the lookup table users away from names towards ids.