Merge branch 'io_matrixmarket_for_multiple_rhs' into 'master'

IO matrixmarket for vectors of simd type

See merge request !368
12 jobs for master in 36 minutes and 56 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Test
passed #244059
duneci
debian-11-gcc-9-17-python

00:24:21

passed #244060
duneci
debian-11-gcc-9-17-with-checking

00:20:24

passed #244051
duneci
debian:10 clang-7-libcpp-17

00:12:45

passed #244049
duneci
debian:10 gcc-7-17

00:12:46

passed #244050
duneci
debian:10 gcc-8-noassert-17

00:25:40

passed #244053
duneci
debian:11 gcc-10-20

00:26:19

passed #244052
duneci
debian:11 gcc-9-20

00:27:45

passed #244054
duneci
ubuntu:18.04 clang-5-17

00:15:35

passed #244055
duneci
ubuntu:18.04 clang-6-17

00:12:34

passed #244058
duneci
ubuntu:20.04 clang-10-20

00:12:47

passed #244057
duneci
ubuntu:20.04 gcc-10-20

00:36:54

passed #244056
duneci
ubuntu:20.04 gcc-9-20

00:29:40