Move random number generator to math-support (!92)

## What is the new feature
Move random number generator to `libmath-support`. (Adds in https://gitlab.dkrz.de/icon-libraries/libmath-support/-/merge_requests/33

)
## How is it implemented
The random number generator module is more suitable to be put into `libmath-support`. Thus we are moving it from `libfortran-support`.

**The next versions `libfortran-support` 2.0.0 and `libmath-support` 1.1.0 should be merged at the same time.**

Approved-by: Daniel Hupp <daniel.hupp@meteoswiss.ch>
Merged-by: Yen-Chen Chen <yen-chen.chen@kit.edu>
Changelog: feature