Feature to auto add custom tag options to generated go structs

[PramodChaitanyakvv]

The following command will auto add provided custom tag options to generated go structs

protoc -I /usr/local/include \
    	-I . \
    	--gotag_out=auto="form-as-camel":. --gotag_opt=suffix="form:optional+required" example/example.proto
  

Generated Go struct
  
type Foo struct {
	Id   string `form:"id,optional,required"`
	Name string `form:"name,optional,required"`
	Age  int    `form:"age,optional,required"`
}

resolution for the following issue #41 (comment)

[mesmerx]

@Kavuti @ucpr this could be a good to add, lets test this