Function format_path 

pub fn format_path(path: &[PathSegment]) -> String

Format a validation path as a clean dotted path: user.email, items[0].name.

No leading dot; an empty path gives an empty string.

use vld::error::PathSegment;
let p = [PathSegment::Field("items".into()), PathSegment::Index(0), PathSegment::Field("name".into())];
assert_eq!(vld_integration_common::format_path(&p), "items[0].name");