Suggest replacing 'iter().any(|x| x == y)' with 'contains' where appropriate

[TheIronBorn]

Particularly for str.chars().any or types with non-default implementations of SliceContains.

[killercup]

this is a good addition to the list in #2401 :)

[camsteffen]

Some cases to include

// yoda condition
vec![1].iter().any(|&n| 1 == n);
// all not equal
vec![1].iter().all(|&n| n != 1);
// slice
|slice: &[u32]| slice.iter().any(|&n| n == 1);
// HashSet or BTreeSet
|set: HashSet<u32>| set.iter().any(|&n| n == 1);
// HashMap or BTreeMap keys
|map: HashMap<u32, u32>| map.keys().any(|&n| n == 1);

// more collections: VecDeque, LinkedList