Async: add sh_ptr<ContinuationChainLink> to Callback<>

This change enables us to finally implement the tracing of
continuations backward from the point of acquisition for deadlock
debugging.

include/user/senseApiDesc.h

@@ -8,6 +8,7 @@
 #include <preprocessor.h>
 #include <componentThread.h>
 #include <user/deviceAttachmentSpec.h>
+#include <callback.h>
 
 namespace smo {
 namespace sense_api {
@@ -44,10 +45,10 @@ typedef int (sal_mlo_finalizeIndFn)(void);
 typedef void (sal_mlo_attachDeviceReqFn)(
     const std::shared_ptr<device::DeviceAttachmentSpec>& desc,
     const std::shared_ptr<ComponentThread>& componentThread,
-    sal_mlo_attachDeviceReqCbFn cb);
+    Callback<sal_mlo_attachDeviceReqCbFn> cb);
 typedef void (sal_mlo_detachDeviceReqFn)(
     const std::shared_ptr<device::DeviceAttachmentSpec>& desc,
-    sal_mlo_detachDeviceReqCbFn cb);
+    Callback<sal_mlo_detachDeviceReqCbFn> cb);
 
 /**
  * @brief Hooks provided by Salmanoff to senseApi libraries.