Consider making `sails-rs` an owner of the `reflect-hash`

[techraed]

reflect-hash is exported as an independent crate, thus defining in reflect_hash attribute a path to ReflectHash trait inner impl functions. It should otherwise be only a part of sails_rs and an attribute must point to the path to sails_rs crate.

#[sails_rs(crate = sails_rs)] // instead of [reflect_hash(crate = sails_rs)]

Originally posted by @vobradovich in #1114 (comment)