Collection of doc fixes for OpenJFX 14

1. FXCollections#reverse is missing a period before "First".

2. Platform#isFxApplicationThread: "Use this call the ensure" --> "to ensure"

3. Node#clipProperty: "the the clipping shape" --> only one "the"

4. checkJavaException function in OleUtils.h, line 230: "Messsge" -> Message

5. Animation#stop: stops an animation in PAUSE too: "If the animation is stopped, this method has no effect."

6. Animation#totalDuration: "A animation" -> "An animation"