[API] Introduce VisualQueryDetectedResult

Introduce the new data class to encapsulate detection results from the
VisualQueryDetectionService and update paired API calls for future
extension.

Bug: 318617199
Test: atest CtsVoiceInteractionTestCases
Flag: ACONFIG android.service.voice.flags.allow_complex_results_egress_from_vqds NEXTFOOD
Change-Id: I9bebb71b1064e2b81a37f584c7af13a9ed8a4759