Use new colorpicker/fontpicker modules

[bergice]

Overview

Since we've refactored the colorpicker and fontpicker parts of this modules out, it would make sense to phase out the old code and use these new modules instead.

Acceptance Criteria

• Add composer require to https://github.com/silverstripe/silverstripe-colorpicker
• Add composer require to https://github.com/silverstripe/silverstripe-fontpicker
• Remove all local code referencing colorpicker
• Remove all local code referencing fontpicker
• Aliases new namespace correctly to avoid breaking API

[robbieaverill]

Please ensure you deprecate the CWP code that you've moved rather than remove it =)