Refactor RegexProperty to use a property type (create RegexType)

[ljacqu]

RegexProperty implements conversions in the class and not via a property type. In a move to make type behavior more reusable, we want to model type conversions as often as possible as a PropertyType for reusability.

To do

• Create RegexType (extends from PropertyAndLeafType)
• Move conversion logic from the RegexProperty to the new type
• Change RegexProperty to extend TypeBasedProperty and to use the RegexType
• Add RegexType to the list of default types in the leaf value handler -> LeafValueHandlerImpl#createDefaultLeafTypes

[sharief007]

Pull Request: #371