Adds the ability to flip (mirror) the display, just like "Flip
Board View" does in Pcbnew.
Also added this to vertical toolbar since it's handy to not
have to go into the menu system to flip the display back and
forth.
Fixes issue https://gitlab.com/kicad/code/kicad/-/issues/2501
It was confusing that the primary frames registered their tools
differently than the other frames. In addition, since the other
frames also added their own tools, foo_actions::RegisterAllTools()
didn't really register all tool but rather those used by the
principal frame (PCB_EDIT_FRAME, SCH_EDIT_FRAME, etc.)
Put the cursor and pan control TOOL_ACTIONs in ACTION,
and refer to them in that way.
The handlers are currently identical in Pcbnew and Cvpcb,
and Gerbview (and all canvases) can benefit from them as well
if they are in libcommon. Also saves duplicated code.
Fixes: lp:1795855
* https://bugs.launchpad.net/kicad/+bug/1795855
PJM
Jeff Young
Seth Hillbrand
John Beard
Maciej Suminski
jean-pierre charras
Jon Evans
Tomasz Włostowski