- add explicit test for "wrongDateFormat" being raised when options.format is given and not satisfied

…d by ember-validators

 - the version from ember-validators does not support "now" or "precision" or "format" correctly, and is unlikely to change to support them
 - indicate that `moment` should be installed in the consuming application, but it does not need to be provided by this package
   - TODO: allow configuring the date library used, e.g. provide a moment validator, a luxon validator, etc, and allow the consuming applications to indicate which kind should be used.

(This can show up in debounced input scenarios, e.g. where a user is editing both a start and an end date.)

ref adopted-ember-addons/ember-validators#85 and adopted-ember-addons/ember-validators#119

 - move new code to "date-moment" validator
 - TODO: ensure moment is actually optional
 - TODO: same approach for luxon

…dator

Ideally we could just link to ember-validators, but they do not offer upgrading guidance

 - Some examples need to be fleshed out further

since optionalDependencies will be attempted for install