Dragging a card into the grid doesn't populate its model with default values

[Alex-Ikanow]

Because that only happens when formly is executed ie when the form is opened

Few options:

• Have an "approximate" model filler-in (eg copy schema.keys.defaultValue -> model, need to be able to recurse through layouts...I think there's possible an issue with nested keys, though that probably wouldn't be a big issue for startup cases?)
• Generate errors for un-opened forms with non-empty schemas
• (Auto open a form when added to the workspace, this is the simplest though makes it a bit annoying if you want to add a bunch of elements and then configure them)
• Provide a default model option (would then replace defaultValue)
• Some combination thereof...

[Alex-Ikanow]

Added a default model, use that instead of default values