Implemented basic observations app

**Currently implemented basic observation app.**
 - Some of the things are hard coded for time being.
 - Later on more features will be added.

**NOTE :**
 - At back-end we need to add group's _Id in GSystemType in Observations collection objects.
 - Then this GSystemType will be appear in that group's Observation app.
 - Due to urgent requirements this thing has been done, which will rectified afterwards.