[FIX] sap.m.ObjectIdentifier: Empty text node will not be rendered

Fixed an issue with the ObjectIdentifier where the empty text node was
reserving extra height. Extended the test page and unit tests.

Change-Id: Ifc104a1c2bc7021158e78c5a044823a562b9730e
BCP: 1482029021
Merge "[FIX] sap.m.ObjectIdentifier: Empty text node will not be rendered"