I'm seeing an issue where the new default prefs (showLineNumbers, styleActiveLine and wordWrap) are not getting added to the ``_prefs`` object. I think this call here should be ``PreferencesManager.getPreferenceStorage(PREFERENCES_CLIENT_ID, defaultPrefs);``. @TomMalbran you did the refactoring here recently...can you clarify?

Looking at ``PreferencesManager.handleClientIdChange()`` it looks like we ignore brand new defaults if we found non-empty preferences for the old ID.

The result here is that the first time I launch with @RaymondLim's changes I lose editor line numbers since ``showLineNumbers`` is undefined.