Continue Breadcrumb Refactoring

- Addresses overlooked header and template files during `Breadcrumb` refactoring.
- Removes `Countable`
- Adds `getLinks()`
- Restores `last()` as deprecated

Code relying on `last()` will continue to work with an `E_USER_DEPRECATED` error being triggered.  It should be replaced with module- or page- related code as page titles are not the responsibility of a breadcrumb class.