Fis issue #116

This pull request fixes the issue #116 Time fields in observation table are identical when executing InsertResult with om:resultTime.
- Problem: SOS did not check the resultStructures swe:field content element definitions for om:resultTime (http://www.opengis.net/def/property/OGC/0/ResultTime)
- Solution:
  - Check and parse om:resultTime if defined
  - Add example requests and JUnit tests
  - Add checks when inserting result template