Lint request: avoid dynamic dispatch

[srawlins]

Dynamic dispatch has several costs: it can be expensive, and can prevent tree-shaking.

The lint rule would report any methods being called on dynamic (other than methods on Object?).

Examples:

var a;
a.length;

getLength(a) {
   print(a.length);
}

[srawlins]

CC @vsmenon @matanlurey

[matanlurey]

10/10 would adopt.

[srawlins]

Oops originally requested by @matanlurey at https://github.com/dart-lang/sdk/issues/33121. Lots of nummy discussion there. But I think this issue does belong here.

[srawlins]

Replacing with #57703