Move emitUnionTypeAnnotation into parsers-primitives (#35502)

Summary:
This PR aims to move  the emitUnionTypeAnnotation function into parsers-primitives.
It was extracted to parsers-commons in a task of #34872. But, all other emit* functions are in this file, so I think it was a mistake.

## Changelog

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[Internal] [Changed] - Move emitUnionTypeAnnotation function into parsers-primitives

Pull Request resolved: #35502

Test Plan:
yarn flow:
<img width="506" alt="image" src="https://user-images.githubusercontent.com/40902940/204494702-4a190d29-38bb-4da3-beb1-236f685ce671.png">

yarn lint:
<img width="261" alt="image" src="https://user-images.githubusercontent.com/40902940/204494798-3dfb0a8a-8535-455c-9483-ec17a7d8a710.png">

yarn test:
<img width="381" alt="image" src="https://user-images.githubusercontent.com/40902940/204494766-27fdaccc-f90d-4b77-b53b-2ff0d720c74e.png">

Reviewed By: rshest

Differential Revision: D41577409

Pulled By: cortinico

fbshipit-source-id: c37b85e8a53c2b1c2bb0e00bc772dd615d1269dd