7387b87bb9
Improve suggestions for several lints This PR is a follow-up of this [Zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/filter_next.20lint). It unifies placeholders for `methods` module and improves several suggestions for `filter_next`, `filter_map_next` and `map_unwrap_or` lints. changelog: none