* new: SensorManager

* BasChatMesh: new onContactRequest(), for PAYLOAD_TYPE_REQ handling.
* companion, repeater and room_server: now with basic 'plumbing' to handle REQ_TYPE_GET_TELEMETRY_DATA (0x03).
* dependency: added CayenneLPP to libdeps
* all target.* modules now with a stub 'sensors' object.

src/helpers/SensorManager.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <CayenneLPP.h>
+
+#define TELEM_PERM_LOCATION   0x02
+
+#define TELEM_CHANNEL_SELF   1   // LPP data channel for 'self' device
+
+class SensorManager {
+public:
+  virtual bool begin() { return false; }
+  virtual bool querySensors(uint8_t requester_permissions, CayenneLPP& telemetry) { return false; }
+  virtual void loop() { }
+};