add constructor and deduction guide for DOFVector

4 jobs for feature/problemstat_construction in 43 minutes and 22 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #20146
dune-2.6

00:24:03

passed #20147
dune-2.7

00:34:04

passed #20148
dune-git

00:32:07

passed #20149
dune-git-full

00:43:21