[C#] Fix field name struct name collision (#6744) (#6757)

* Fix C/C++ Create<Type>Direct with sorted vectors

If a struct has a key the vector has to be sorted. To sort the vector
you can't use "const".

* Changes due to code review

* Improve code readability

* Add generate of JSON schema to string to lib

* option indent_step is supported

* Remove unused variables

* Fix break in test

* Fix style to be consistent with rest of the code

* [C#] Fix field name struct name collision (#6744)

src/idl_gen_csharp.cpp

@@ -619,6 +619,7 @@ class CSharpGenerator : public BaseGenerator {
       std::string dest_cast = DestinationCast(field.value.type);
       std::string src_cast = SourceCast(field.value.type);
       std::string field_name_camel = MakeCamel(field.name, true);
+      if (field_name_camel == struct_def.name) { field_name_camel += "_"; }
       std::string method_start =
           "  public " + type_name_dest + optional + " " + field_name_camel;
       std::string obj = "(new " + type_name + "())";