Remove mjTIMER_ACCELERATION, add mjTIMER_ADVANCE.

- mjTIMER_ACCELERATION is not very useful, it's usually very tiny (0.5% for humanoid, 1% for 22humanoids). It basically times a single call to `mj_solveM`.

- Added `mjTIMER_ADVANCE` to time `mj_Euler` and `mj_implicit` (which can be significant).

- Moved `mj_transmission` to `mjTIMER_KINEMATICS` where it belongs (and used to be).

PiperOrigin-RevId: 565936880
Change-Id: I26b8a067133594e5500ca1c809beb3518b4a8d9c

unity/Runtime/Bindings/MjBindings.cs

@@ -129,8 +129,8 @@ public enum mjtTimer : int{
   mjTIMER_POSITION = 3,
   mjTIMER_VELOCITY = 4,
   mjTIMER_ACTUATION = 5,
-  mjTIMER_ACCELERATION = 6,
-  mjTIMER_CONSTRAINT = 7,
+  mjTIMER_CONSTRAINT = 6,
+  mjTIMER_ADVANCE = 7,
   mjTIMER_POS_KINEMATICS = 8,
   mjTIMER_POS_INERTIA = 9,
   mjTIMER_POS_COLLISION = 10,