Update geometry view regression check files

- Geometry views no longer use variable length strings.
- Fine geometry views (GeometryViewLines) now correctly order materials
  (alphabetically by ID).

reframe_tests/regression_checks/TestGeometryView_5176823e/full_volume.vtkhdf

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:4a8134fca3e6228211e4a4bc3e504e64f888c55f22e025b482ec501e0051d253
-size 75740296
+oid sha256:c7c7303daffcd4debb8df4c0c5e6cd62a6fd07c6e4b33e8c47c9e190c42d75cf
+size 75736481

reframe_tests/regression_checks/TestGeometryView_5176823e/partial_volume.vtkhdf

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:2ccd95ff4ef73c224c99a8c321ad6f8014c673a1b33bbb741bff415dfbffd0aa
-size 4931176
+oid sha256:a0a195bfeec73f72083e6dbeb5e3713259721d2d4e9118bf019ee9905f02f5a8
+size 4927361

reframe_tests/regression_checks/TestGeometryView_77980202/full_volume.vtkhdf

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:82b8ac914a9fe20b49f2512215782f01305a2e3211aaac51913f88296a0e3ac5
-size 4012444
+oid sha256:67c7c15c0025feac5b5899c3a691929ae1d7338c68714708c7a41e51a7f71441
+size 4009216