Extend safeHref

[colinlohner]

An update to the safeHref functionality to better support our users

• Removed data: protocol from safe protocols to further protect users
• Added ability to pass custom "safe" protocols to the configureSafeHref method
• Added ability to allow custom protocols on a component usage level allowProtocols
• Fixed a situation where if whitespace led a url you could bypass protocol safety
• Added some basic testing around the functionality of safeHref