Merge branch 'feature/restructure_mpl' into 'develop'

split Mpl into Index, Logical, Range

See merge request !94
4 jobs for develop in 30 minutes and 56 seconds (queued for 53 minutes and 55 seconds)
Status Job ID Name Coverage
  Test
passed #8656
debian:10 clang-6-libcpp-17

00:24:37

passed #8655
debian:10 gcc-8-17

00:18:28

passed #8657
debian:9 gcc-6-14

00:18:44

passed #8658
ubuntu:18.04 clang-6-17

00:22:21