Final refactor for bfsb_generator* and text generator (#7806)

* Refactor BfbsGenerator to use CodeGenerator interface

* Update

* Refactor bfbs generator

* Refactor bfbs generator for lua and nim. Remove old code that use Generator
interface.

* Update import

* Update CMakeLists

* Update BUILD file

* Update BUILD file for src

* Remove from Android CMakeLists and add error message

* Update

* Add generate root file function to Code Generator interface

* Update

* Update

* Minor format fix

src/idl_gen_text.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2023 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_IDL_GEN_TEXT_H_
+#define FLATBUFFERS_IDL_GEN_TEXT_H_
+
+#include "flatbuffers/code_generator.h"
+
+namespace flatbuffers {
+
+// Constructs a new Text code generator.
+std::unique_ptr<CodeGenerator> NewTextCodeGenerator();
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_IDL_GEN_TEXT_H_