Wakeword and Keyword Spotting application

Topics
	DMIC control functions
	Keyword spotting model functions
	LEDs control functions
	Printing control output functions
	Wakeword model functions
static int	init_app_ble (void)
static int	obsv_model_info_from_model (nrf_edgeai_t *model, uint16_t num_classes, nrf_edgeai_obsv_model_info_t *info)
	Fill observability model metadata from an nRF Edge AI model instance.

Detailed Description