[fix] Next/Previous frame was jumping some frame

When the user try to move frame by frame, some frames were skipped. This was
due to the wrong play mode been set before calling GoToPrevious or GoToNext.
There was an additional issue when the user selected 'ALL Frame' in the
PlayerControlerToolbar.

The wrong enum has been use all over this file.

ApplicationComponents/lqPlayerControlsController.cxx

@@ -46,6 +46,9 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <vtkSMPropertyHelper.h>
 #include <vtkSMIntVectorProperty.h>
 
+// vtkAnimationScene doesn't have a enum for PLAYMODE_SNAP_TO_TIMESTEP despite this mode is implemented
+constexpr int PLAYMODE_SNAP_TO_TIMESTEP = 2;
+
 // Scene Property Helpers
 namespace {
 void SetProperty(QPointer<pqAnimationScene> scene, const char* property, int value)
@@ -243,7 +246,7 @@ void lqPlayerControlsController::setSceneTime(double time)
 void lqPlayerControlsController::onNextFrame()
 {
   // need to change the mode as in realtime next frame is actually t = t+1s
-  SetProperty(this->Scene, "PlayMode", vtkAnimationScene::PLAYMODE_SEQUENCE);
+  SetProperty(this->Scene, "PlayMode", PLAYMODE_SNAP_TO_TIMESTEP);
   this->Scene->getProxy()->InvokeCommand("GoToNext");
 }
 
@@ -251,7 +254,7 @@ void lqPlayerControlsController::onNextFrame()
 void lqPlayerControlsController::onPreviousFrame()
 {
   // need to change the mode as in realtime previous frame is actually t = t-1s
-  SetProperty(this->Scene, "PlayMode", vtkAnimationScene::PLAYMODE_SEQUENCE);
+  SetProperty(this->Scene, "PlayMode", PLAYMODE_SNAP_TO_TIMESTEP);
   this->Scene->getProxy()->InvokeCommand("GoToPrevious");
 }
 
@@ -262,7 +265,8 @@ void lqPlayerControlsController::setPlayMode(double speed){
 
   if (speed <= 0)
   {
-    SetProperty(this->Scene, "PlayMode", vtkAnimationScene::PLAYMODE_SEQUENCE);
+    // There is no enum for
+    SetProperty(this->Scene, "PlayMode", PLAYMODE_SNAP_TO_TIMESTEP);
   }
   else
   {