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/MyGame/Example/Color.lua

@@ -2,9 +2,13 @@
 
 -- namespace: Example
 
+-- Composite components of Monster color.
 local Color = {
     Red = 1,
+    -- \brief color Green
+    -- Green is bit_flag with value (1u << 1)
     Green = 2,
+    -- \brief color Blue (1u << 3)
     Blue = 8,
 }