The initial click is ignored on macOS, requires mouse movement before the second click works correctly

[robbert-vdh]

When embedding a baseview window inside another window using the open_parented() function on macOS, the first click on the window only focuses the window and doesn't trigger a mouse button down event for the window handler. Additionally, after this first click the user needs to wiggle their mouse around a bit because up until that point no mouse movement event will have been sent to the window. The view overrides the acceptsFirstMouse method, but it never seems to be fired. And the tracking areas should allow the plugin to receive mouse movement updates when the user hovers over an unfocused baseview window but that also doesn't seem to work.

I tested this on macOS Catalina with the NIH-plug plugins and OctaSine, and also with the NIH-plug standalones which embed a baseview window inside of another blocking baseview window.