KeyBindingManager no longer warns / prevents binding collisions

[peterflynn]

Place the following code in an extension:

KeyBindingManager.addBinding(Commands.FILE_OPEN_FOLDER, "Ctrl-E");

Result: Quick Edit binding is silently overwritten. No console warnings.

Expected: We used to print warning messages and ignore the attempt at overwriting the binding. KeyBindingManager._addBinding() still contains several bits of code that seem like they should do this, but the logic has gotten pretty convoluted so I'm not sure in which cases they'll run anymore.

[peterflynn]

Here's the original repro case, slightly trickier, that I found in the Clojure extension:

    KeyBindingManager.addBinding(Commands.FILE_OPEN_FOLDER, [
        {
            "key": "Ctrl-E"
        },
        {
            "key": "Cmd-E",
            "platform": "mac"
        }
    ]);

[njx]

Reviewed. Low priority to @dangoor

[jasonsanjose]

FBNC @peterflynn. We still allow platform-specific overrides to clobber a generic binding, but not the other way around. @WebsiteDeveloper's fix will show errors in the case you've described here as well when clobbering a generic binding with another generic binding.

[peterflynn]

We certainly do warn now, though not always at the right times -- see #4265 for more up to date discussion. Closing this one.

[redmunds]

Verified that this is fixed in pull request #5066.