Possibility to disable core functions

[skyper]

comment:23 on #7328 by akks:

By the way, disabling core actions, mapmodes, or toggle dialogs can be implemented easily. No one ever asked to do it) Do you think it can help to work on slow machines?

All we need to do is to add "if" to their initialization lines:

        addMapMode(new IconToggleButton(new ExtrudeAction(this), true));
        addMapMode(new IconToggleButton(new ImproveWayAccuracyAction(Main.map), true));
...
        addToggleDialog(filterDialog = new FilterDialog());
        addToggleDialog(new ChangesetDialog(this), true);
        addToggleDialog(new MapPaintDialog());

and make proper configurator.

Think this could help not only on slower machines and also to make a customized version.

There is also #4614.