Delete joistVoicingUtteranceQueue and replace with voicingVisibleProperty

[jessegreenberg]

Now that voicingVisibleProperty is ready for use I think it can be used instead of the joistVoicingUtteranceQueue. The joistVoicingUtteranceQueue is problematic because priorityProperty doesn't work well with multiple UtteranceQueues (see #752 (comment)).

[jessegreenberg]

At this time the only usage of joistVoicingUtteranceQueue is in VoicingToolbarItem, other than controlling its enabled state in audioManager and a phet-io specific thing in Sim.js.

[jessegreenberg]

joistVoicingVisible has been removed. I added a function to Sim.js to set components other than the toolbar to voicingVisible: false so that they are not heard. It is called when voicingFullyEnabledProperty changes (which is what previously controlled the enabled state of joistVoicingUtteranceQueue.

It isn't working quite yet but I expect that it will. We need to do phetsims/scenery#1403 to verify that voicingVisibleProperty is correctly preventing speech when voicingFullyEnabledProperty if false.

[jessegreenberg]

voicingVisibleProperty is working as a replacement of the joistVoicingUtteranceQueue. The feature of the "Sim Voicing" toggle switch in the toolbar isn't working everywhere yet because we still have decisions to make in phetsims/scenery#1403. Nothing further to be done in this issue.

[jessegreenberg]

This should be reviewed as part of phetsims/scenery#1300, assigning to @zepumph as part of that. And thanks!

[jessegreenberg]

One improvement is to rename setSimVoicingVisible to setSimContentVoicingVisible.

We need to update voicingVisible somehow in setAccessibleViewsVisible. We also need explicit control over how voicingVisible is enabled for the Toolbar and topLayer (dialogs) we thought it would be good to have two functions for each of those so that setting is clear.

Also, the call to setSimVoicingVisible is in a listener added in Sim.js if the Toolbar is provided. It would be better in Toolbar. Can add this listener when sim.isConstructionCompleteProperty fires so that ScreenViews are initialized.

Back to me for these things.

[zepumph]

Ok sounds good. Let me know if I can assist at all.