fix: add whitespace in macro for delegate assists

[A4-Tacks]

• Move pretty_pat_in_macro to utils
• Insert ws out of node for prettify_macro_expansion
• Pretty in macro for generate_delegate_methods
• Pretty in macro for generate_delegate_trait

Before:

pub fn test(self,b: &mutbar::Bar) ->bar::Bar {
    self.bar.test(b)
}

After:

pub fn test(self,b: &mut bar::Bar) -> bar::Bar {
    self.bar.test(b)
}