Add extended return format

[bramus]

See #1 (comment) (and follow-up comments) for discussion.

The idea it to allow one to choose between returning only the value, or returning a more extended object that holds more info.

[
  {"propertyName": "margin", "value": "40px", "previousValue": "20px", "changed": true},
  {"propertyName": "color", "value": "rgb(0, 0, 0)", "previousValue": "rgb(0, 0, 0)", "changed": false}
]

This would be opt-in, through an option named ReturnFormat: VALUE_ONLY (default) or OBJECT

[faizanu94]

Hey @bramus - I've now implemented this feature in this PR - following our decision to split this from the optimized change detection PR. I’ve focused on enhancing modularity and introduced a flag for backward compatibility