version-aware implementation for deserialize and deserializeRT in order ...

...to support v3.0

fixes #123 

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Currently tested with:
__UR5__
- [x] 1.6
- [x] 1.7
- [x] 1.8
- [x] 3.0

__UR10__
- [x] 1.6
- [x] 1.7
- [x] 1.8
- [ ] 3.0


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__Note__
This PR does not include the fixes for the MoveIt! configs!