1. Add api ssc cmd "ap -K -a aid" to kick out connected station.

The parameter aid followed -a is aid of the connected station. If aid is 0, kick out all of the connected stations.
2. Add block parameter to api esp_wifi_scan_start.
   If block is true, the api blocks before scan done or returns directly.

components/esp32/include/esp_event.h

@@ -48,6 +48,7 @@ typedef struct {
 typedef struct {
     uint32_t status;          /**< status of scanning APs*/
     uint8_t  number;
+    uint8_t  scan_id;
 } system_event_sta_scan_done_t;
 
 typedef struct {