Migrate certain can-util imports away from can-util if independent packages exist.

[bmomberger-bitovi]

can-util is large and clunky. Though it still contains useful utilities, its most useful ones have been moved out into their own packages (e.g. can-assign, can-ajax, can-dom-data) and are transparently included by can-util. Additionally, can-util warns users to use the individual package instead of the deprecated version in can-util. The Can 6 upgrade process should include a codemod to use lower level packages where possible so that applications can remove the can-util dependency where possible.