(feat): Unpack extensions into complex function types #8

The more in-depth we use extensions, the more likely is is that we need custom extensions. New `UnpackExtensions` function in the high package makes this easy. Low level models have been updated to support feature fully and docs added in README and examples as well.

Signed-off-by: Dave Shanley <dave@quobix.com>

datamodel/low/reference.go

@@ -34,6 +34,8 @@ type Hashable interface {
 
 // HasExtensions is implemented by any object that exposes extensions
 type HasExtensions[T any] interface {
+
+	// GetExtensions returns generic low level extensions
 	GetExtensions() map[KeyReference[string]]ValueReference[any]
 }