Added support for msh2.2

Now we can load flex with format 2.2 binary and ASCII.
There are two different parsing strategies. One for gmsh app and the other is for ftetwild.

Used the shark model from Scanned Objects by Google Research:
https://app.gazebosim.org/GoogleResearch/fuel/models/Weisshai_Great_White_Shark

PiperOrigin-RevId: 619229499
Change-Id: I6eb876afcbc8a00631914b093c45bde10c0caaf6

test/sample/testspeed_test.sh

@@ -32,8 +32,14 @@ test_model() {
       # this test can take several minutes under ASAN
       return 0
     fi
-    if [[ "$model" == */benchmark/testdata/humanoid200.xml
-        || "$model" == */engine/testdata/collision_convex/stacked_boxes.xml
+    if [[ "$model" == */benchmark/testdata/humanoid200.xml ||
+          "$model" == */engine/testdata/collision_convex/stacked_boxes.xml ||
+          "$model" == */user/testdata/shark_41_ascii_gmshApp.xml ||
+          "$model" == */user/testdata/shark_22_ascii_fTetWild.xml ||
+          "$model" == */user/testdata/shark_22_ascii_gmshApp.xml ||
+          "$model" == */user/testdata/shark_22_binary_fTetWild.xml ||
+          "$model" == */user/testdata/shark_41_binary_gmshApp.xml ||
+          "$model" == */user/testdata/shark_22_binary_gmshApp.xml
     ]]; then
       iterations=2
     fi