Error message customization

[knvpk]

As of now, the error message is creating automatically with attribute value, but it should be customizible in some cases we need to show error message differently.

[danvick]

Thanks for your helpful feedback @pavankumarkatakam.
This too has been addressed in the upcoming version.

[knvpk]

Ok, Thanks for the reply. For now, I'm using plain Flutter in built forms, but this package will solve many problems and less boilerplate code.