Fix multi-line comments for cpp enums (#5345) (#5346)

- fix CSharp comments generation
- fix Python comments generation
- fix Lua comments generation
- fix PHP comments generation
- fix Dart comments generation
- add brief description of Color enum
- add multi-line comments to the Monster:Color

tests/monster_test_generated.ts

@@ -1,12 +1,23 @@
 // automatically generated by the FlatBuffers compiler, do not modify
 
 /**
+ * Composite components of Monster color.
+ *
  * @enum {number}
  */
 export namespace MyGame.Example{
 export enum Color{
   Red= 1,
+
+  /**
+   * \brief color Green
+   * Green is bit_flag with value (1u << 1)
+   */
   Green= 2,
+
+  /**
+   * \brief color Blue (1u << 3)
+   */
   Blue= 8
 }};