stateSchema bug validating between value vs composite schemas

[zepumph]

Related to work in #245,

@jessegreenberg and I found a bug where because a stateschema was given a composite schema (Vector2IO) incorrectly, and should have been given a value stateSchema (NullableIO( Vector2IO )), when passing in a value (null), we got a truly atrocious error message:

Error: TypeError: Cannot read properties of null (reading 'hasOwnProperty')
    at eval (eval at <anonymous> (StateSchema.js:169), <anonymous>:1:14)
    at StateSchema.js:169
    at Array.forEach (<anonymous>)
    at checkLevel (StateSchema.js:167)
    at StateSchema.checkStateObjectValid (StateSchema.js:179)
    at IOType.isStateObjectValid (IOType.js:334)
    at IOType.validateStateObject (IOType.js:376)
    at StateSchema.js:174
    at Array.forEach (<anonymous>)
    at checkLevel (StateSchema.js:167)

Basically, when you get down to it, checkLevel expects a composite stateObject (an object), but it was null, a valid value for NullableIO(Vector2IO).

We can use SceneryEventIO to achieve this in the mirror inputs wrapper when you select a menu item with keyboard navigation.

The purpose of this issue is to make a better assertion earlier in the chain.

[samreid]

The mirror inputs wrapper isn't working at the moment. Something about the resizeAction getting [x,y] instead of {x,y}? I wonder if @zepumph and I will visit this issue when we work on #282?

[samreid]

I did not have time to address this issue during this iteration, and am not planning to work on it soon. Unassigning for now.

[zepumph]

If we encounter this bug during serlization again, that will help raise this issue's priority. We will more likely not encounter it in the same way as when originally reported (keyboard nav + input event recording + specific case).