Updates to MooseVariableInterface and variable getter APIs to incorporate vector finite elements

Needs to wait for https://github.com/idaholab/moose/pull/10238
8 jobs for interface-changes in 15 minutes and 31 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build Libmesh
passed #8694
build_libmesh_job

00:11:34

 
  Configure Giraffe
passed #8695
configure_giraffe_job

00:00:14

 
  Build Giraffe
passed #8742
build_giraffe_job

00:00:10

failed #8696
build_giraffe_job

00:10:35

 
  Run Giraffe Serial
passed #8697
run_giraffe_serial_job

00:02:56

 
  Verify Giraffe Serial
passed #8698
verify_giraffe_serial_job

00:00:00

 
  Run Giraffe Parallel
passed #8699
run_giraffe_parallel_job

00:00:34

 
  Verify Giraffe Parallel
passed #8700
verify_giraffe_parallel_job

00:00:00