implement macro FWD() directly using static_cast instead of std::forward

4 jobs for feature/forward in 42 minutes and 28 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #20976
dune-2.6

00:25:23

passed #20977
dune-2.7

00:33:13

passed #20978
dune-git

00:33:12

passed #20979
dune-git-full

00:42:27