feat: expose codegen headers for SDK

Author: zaucy

BUILD.bazel

@@ -2,6 +2,14 @@ load("@rules_cc//cc:defs.bzl", "cc_library")
 
 package(default_visibility = ["//visibility:public"])
 
+filegroup(
+    name = "headers",
+    srcs = glob([
+        "ecsact/codegen/*.hh",
+        "ecsact/codegen/*.h",
+    ]),
+)
+
 cc_library(
     name = "plugin_validate_headers",
     hdrs = [