Suggestion: Use Keys/Values enumerators when possible, instead of KeyValuePair enumerator

[wiz0u]

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Collections of type IDictionary<TKey, TValue> implement IEnumerable<KeyValuePair<TKey, TValue>> and also offer direct Values and Keys enumerators.

For these collections, I would like Roslynator to identify this kind of LINQ expression: collection.First().Key or collection.First().Value and suggest to refactor it as collection.Keys.First() or collection.Values.First()

I feel the Keys and Values enumerators are always more efficient than the construction of several KeyValuePair (not usually a native construction of the collection) just for the purpose of accessing their .Key or .Value component

These suggestions should at least be compatible with these LINQ methods: ElementAt, ElementAtOrDefault, First(), FirstOrDefault(), Last(), LastOrDefault(), Single(), SingleOrDefault().

To go further, Min, Max, Sum, Average, Count with selectors, and overloads of the preceding methods taking a predicate, could be also be compatible if it is identified that only the adequate .Key or .Value component is used on the lambda-expression argument KeyValuePair