add feature can auto add nested local package's function in go .

[soluty]

Is your feature request related to a problem? Please describe. #249

Describe the solution you'd like if i select a function to run , if the function called other packeages functions, it works fine, but if the function called current packages function, it cannot work because the genarate code only add my real select function, it will be big help to parse package and add it to generated code.

Additional context i dont know whether if other lang can do this, but because of golang only support package level function ,so do this may be not very hard.