add fixed length array support for typescript

[altaroca]

I have added fixed length array support (#5313) for typescript. Needed this for a project of mine. I have not done intensive testing. It works for my project though. Thought this would benefit others.

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[dbaileychess]

@altaroca Any update to this?

[altaroca]

sorry for the delay. this is on my list for when i get back from vacation