Curved ratsnest UI issues.

[Michael Kavanagh]

Following from: https://bugs.launchpad.net/kicad/+bug/1766597 "fixed" in commit e7d32c54b90297554c0193e71c620f5ee78e5164.

* The icon in the toolbar should be in the group with the other (Show/Hide Ratsnest) button.
* We shouldn't use the term `airwire`, rather `ratsnest` like we do everywhere else.
* There should be a checkable menu item in the View menubar menu, in the same group as "Show Ratsnest".
* Maybe this should also go in the Preferences dialog? I'm torn on this one...

A lot of effort has been put in recently to make the UI more coherent across the suite, it would be a great shame to see this slide downhill again.

IMO, all the options like this should not be on a toolbar (by default at least, there will be too many in the future). Moving forward I think we should group options like these into tabbed, dockable panels. I'll try to put together a proposal and post it to the dev mailing list, but I'm aware of the limitations to wxAUI at the moment.

[jean-pierre charras (jp-charras)]

@Michael,

I just committed your patch. Thanks.

[John Beard (john-j-beard)]

WRT to tabbed panels and so on, I did a little research, as far as I know:

* wxAUI doesn't supports vertical ribbon bars
* If you use dropdown tools (the ones with a little arrow on the right) you can't have them also "checkable" (with a boolean state).
* Dropdown tools don't work on Mac
* You can't have a right click handler on a "normal" wxToolbar's tool
* It doesn't say you *can't* have a right click handler on a wxAuiToolbar's tool (this is what we have right now).

At least on Linux, you can fairly easily pop a menu on right click (see attachment).

A common affordance for this is a small triangle or dot in the bottom right of the icon to indicate there's a secondary menu.

Code is something like this (this is obviously just a demo and doesn't actually hook into anything),
so it's relatively tractable. E.g. PCB_EDIT_FRAME::PCB_EDIT_FRAME():

    m_optionsToolBar->Bind(wxEVT_AUITOOLBAR_RIGHT_CLICK, [=](wxAuiToolBarEvent& aEvt) {
        wxLogDebug("rclick id %d", aEvt.GetId() );
        auto* menu = new wxMenu();

        wxMenuItem* item = new wxMenuItem( menu, wxID_ANY, "Item 1" );
        item->SetBitmap( KiScaledBitmap( curved_ratsnest_xpm, this ) );

        menu->Append( item );

        item = new wxMenuItem( menu, wxID_ANY, "Item 2", wxEmptyString, wxITEM_CHECK );
        menu->Append( item );

        m_optionsToolBar->PopupMenu(menu, aEvt.GetClickPoint().x, aEvt.GetClickPoint().y);
    }, wxID_ANY);