Adds implementation flag for swift (#7202)

* Adds implementation flag for swift

Forces internal flag when using @_implementationOnly in swift

Fixes access type for verifier functions & encoder functions

Updates generated code

* Addresses PR comments & adds a code gen dir within the swift tests

* Adds test case for no-include

* Fixes code gen script

Removes prefix

scripts/generate_code.py

@@ -63,6 +63,7 @@ assert flatc_path.exists(), "Cannot find the flatc compiler " + str(flatc_path)
 
 # Specify the other paths that will be referenced
 tests_path = Path(root_path, "tests")
+swift_code_gen = Path(root_path, "tests/FlatBuffers.Test.Swift/CodeGenerationTests")
 samples_path = Path(root_path, "samples")
 reflection_path = Path(root_path, "reflection")
 
@@ -138,6 +139,12 @@ RUST_SERIALIZE_OPTS = BASE_OPTS + [
 TS_OPTS = ["--ts", "--gen-name-strings"]
 LOBSTER_OPTS = ["--lobster"]
 SWIFT_OPTS = ["--swift", "--gen-json-emit", "--bfbs-filenames", str(tests_path)]
+SWIFT_OPTS_CODE_GEN = [
+    "--swift", 
+    "--gen-json-emit",
+    "--bfbs-filenames",
+    swift_code_gen
+]
 JAVA_OPTS = ["--java"]
 KOTLIN_OPTS = ["--kotlin"]
 PHP_OPTS = ["--php"]
@@ -380,6 +387,18 @@ flatc(
     prefix=swift_prefix,
 )
 
+flatc(
+    SWIFT_OPTS_CODE_GEN + BASE_OPTS + ["--grpc", "--swift-implementation-only"],
+    schema="test_import.fbs",
+    cwd=swift_code_gen
+)
+
+flatc(
+    SWIFT_OPTS_CODE_GEN + NO_INCL_OPTS + ["--grpc"],
+    schema="test_no_include.fbs",
+    cwd=swift_code_gen
+)
+
 # --filename-suffix and --filename-ext tests
 flatc(
     CPP_OPTS + NO_INCL_OPTS + ["--filename-suffix", "_suffix", "--filename-ext", "hpp"],