Read persistent triggers from storage

Read json storage file for persistent triggers.
Add trigger to telemetry service.
Cover code with UTs.

Tested:
  - Passed unit tests
  - Tested on QEMU
    * starting app without configuration
    * restart app with configuration stored
    * restart app with configuration in incorrect version
    * restart app with configuration malformed

Change-Id: I2cb9324abdb8323be8a7f0c932ed7f70c5bc2891
Signed-off-by: Cezary Zwolak <cezary.zwolak@intel.com>
Signed-off-by: Lukasz Kazmierczak <lukasz.kazmierczak@intel.com>
diff --git a/tests/meson.build b/tests/meson.build
index d2e5aac..e87a616 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -25,6 +25,7 @@
             '../src/trigger_actions.cpp',
             '../src/trigger_factory.cpp',
             '../src/trigger_manager.cpp',
+            '../src/utils/conversion_trigger.cpp',
             'src/dbus_environment.cpp',
             'src/main.cpp',
             'src/stubs/dbus_sensor_object.cpp',