Open-space-toolkit-mathematics

What's Changed
* refactor: add `Type` to interpolator class and factory method for usability by apaletta3 in https://github.com/open-space-collective/open-space-toolkit-mathematics/pull/110


**Full Changelog**: https://github.com/open-space-collective/open-space-toolkit-mathematics/compare/2.0.0...2.0.1

**refactor:**
- remove test.hpp class from include folder
- align namespaces to singular and expand top level namespace

**build:**
- update Core to 2.1.0

- fix: normalize output of Polygon::getNormalVector

**refactor**
- rename plural namespaces to singular for alignment 102

**refactor**
- explicit namespacing for trf::rot -> transformations::rotations (101)