You can now choose the behavior of dragging with the
middle and right mouse buttons.
You can also choose which modifier keys to use for
panning and zooming with the scroll wheel or trackpad.
You can also customize the zoom speed, which makes
it possible to have a good zoom experience on a wider
range of input devices.
You can also now zoom by dragging with the right or
middle button if desired.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/3885
Fixes https://gitlab.com/kicad/code/kicad/-/issues/4348
Move the camera out to its own so that everything else is board-
related, and then rename BOARD_ADAPTER.
At some point the flags should probably be moved out too, and they
can have the EDA_3D_SETTINGS name.
Jon Evans
Mario Luzeiro
Jeff Young