Add GET method for TriggerCollection

Added GET method for retrieving list of Triggers from Telemetry service

Tested:
- Added single Trigger and requested result from bmcweb via
  /redfish/v1/TelemetryService/Triggers
- Added multiple Triggers numeric and discrete, and requested results
  from bmcweb via /redfish/v1/TelemetryService/Triggers
- Verified uri /redfish/v1/TelemetryService/Triggers by using
  Redfish-Service-Validator with no Triggers/empty Collection (passed)

Signed-off-by: Lukasz Kazmierczak <lukasz.kazmierczak@intel.com>
Change-Id: Ide00eb44901ea1b97b80fc5c5ddfd97e393d4a04
diff --git a/redfish-core/include/redfish.hpp b/redfish-core/include/redfish.hpp
index 2479332..e56996d 100644
--- a/redfish-core/include/redfish.hpp
+++ b/redfish-core/include/redfish.hpp
@@ -41,6 +41,7 @@
 #include "../lib/task.hpp"
 #include "../lib/telemetry_service.hpp"
 #include "../lib/thermal.hpp"
+#include "../lib/trigger.hpp"
 #include "../lib/update_service.hpp"
 #include "../lib/virtual_media.hpp"
 
@@ -206,6 +207,7 @@
         requestRoutesMetricReportDefinition(app);
         requestRoutesMetricReportCollection(app);
         requestRoutesMetricReport(app);
+        requestRoutesTriggerCollection(app);
     }
 };