Api changes in AddReportFuture version

Added support for CollectionFunction, CollectionDuration,
CollectionTimeScope, ReportUpdates, AppendLimit.

New API separates Id and Name, user can decide to pass only Name
to auto generate Id or pass Id which needs to be unique.

Tested:
- No functional changes to old API, everything works as before
- All use cases can be replaced with new API to achieve same results
- New features which require new API work as expected

Signed-off-by: Krzysztof Grobelny <krzysztof.grobelny@intel.com>
Change-Id: I647efab36d90a548754f89968223e162a087481e
diff --git a/src/interfaces/sensor.hpp b/src/interfaces/sensor.hpp
index 65d3c21..6a6bcf7 100644
--- a/src/interfaces/sensor.hpp
+++ b/src/interfaces/sensor.hpp
@@ -43,6 +43,7 @@
     virtual ~Sensor() = default;
 
     virtual Id id() const = 0;
+    virtual std::string metadata() const = 0;
     virtual void registerForUpdates(const std::weak_ptr<SensorListener>&) = 0;
     virtual void
         unregisterFromUpdates(const std::weak_ptr<SensorListener>&) = 0;