delete TVec, refactor DataSpace

DataSpace and TVec was very hard ensnared, therefor DataSpace was also re factored in this pull.

- delete TVec and use CT::Vector
- clean DataSpace methods (most of these already defined in the base class)
- delete implicit cast of DataSpace to dim3  (now explicit with: `toDim3()` )
- refactor SharedBox (was specialized with TVec)
- fix all parts of PMacc, GoL example and picongpu which has used old TVec


*Help to review this big pull:* 
- read commit by commit
- class rewrites are in separate commits

- [x] Tested with KHI default settings