Expose AppOptions and correct its types

[mvaligursky]

• based on Add JSDoc typeof support via JSDoc plugin #5882
• exposes AppOptions class as an public API
• fixed up some types in it (now that we can), which allows us to remove many ts-ignore tags from the examples

[mvaligursky]

What am I missing here @kungfooman ?

Error: build/playcanvas.d.ts(22879,30): error TS2693: 'ResourceHandler' only refers to a type, but is being used as a value here.

[kungfooman]

@mvaligursky You can't do typeof on an interface, that's why I tried to push it here a bit: #5882 (comment)

In short, we have to come to a solution here: #5574 (looks kinda minor, but no response since November last year)

[mvaligursky]

I suspected this :(
Well, we're switching from jsdocs to tsdocs just now .. so that issue might go away I hope.

[mvaligursky]

Actually, that won't help. We need the fix / refactor you mentioned.