Support for date and time types

[mike-hogan]

Make date and time types available as a plugin

Issues to consider:

• how to migrate back and forth between data and the other data types - especially if this "plugin" should not be aware of the other data types!

[mike-hogan]

This has uncovered some core features:

• [ ] Properties need to be able to extend global tenant config. Case in this point is, tenant date format
• [ ] Tenant config needs to use the property-contributed config ui elements
• [ ] Tenant config needs to be passed to validation of values, and property viewers, so data and visualisation decisions can be made
• [ ] Tenant config needs to be persisted

[mike-hogan]

This is now done