Adds embedded data specifications

- Adds missing elements in DataSpecificationIEC61360Content
- Harmonizes HasDataSpecification
- Fixes HasDataSpecification serialization
- Modifies tests according to the changes

Change-Id: I8394c2dbca06ad3c8662a793ba8272765e890acd
Signed-off-by: Daniel Espen <daniel.espen@iese.fraunhofer.de>
45 files changed