Semantic registry validation

- Generated registry validation always re-renders recorded semantics with the current fixer
- Validation canonicalizes the rendering like the installer
- Renderer changes need no version bump
- The renderer identity SPI, both identity strings and the identity-based source preference are gone
- New captures record the fixer class as an informational renderer identity
- The v1 history format is unchanged
- The modded forced datapack, world check and datapack command use the runtime data version
- That is the same data version validation uses
- Tests cover a renderer change under an unchanged identity
- Tests cover 26.3 bare natural_mob_spawns history against the overlay rendering
- Tests cover semantic round trips for every supported fixer

spi/src/main/java/art/arcane/iris/spi/PlatformGenerationRegistry.java

@@ -11,8 +11,6 @@ public interface PlatformGenerationRegistry extends NativeGenerationRegistry {
 
     String runtimeIdentity();
 
-    String generatedDefinitionRendererIdentity();
-
     default String customBiomeResourceKey(String identitySha256) {
         return contentAddressedCustomBiomeResourceKey(identitySha256);
     }