After commit 9535153f9e there were no more IDs inside the legacy ID
system. Therefore the entire system for dispatching and looking up
the legacy ideas and handling those events can now be removed and
the tool dispatcher simplified (it no longer needs to know about
the ACTIONS class).
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