2d arrow and text annotation
We need to add an 2d arrow to the Sources. Maybe call it Annotate Arrow? This arrow will float on top of the data and not move with the camera. We also need this arrow to have optional text. Allow user to change the size of the arrow and text, and color of arrow and text. Allow it to be placed with a placement widget, same as we do for the line tool in Plot Over Line. Allow arrow to be rotated. See screenshot of what I am looking for. 2d Glyph isn't sufficient (it is hollow and rotates with the camera), Arrow is not sufficient (it is 3d, and rotates with the camera).