Update constants as primitives

What does this MR do and why?

This MR refactors the constants to be primitives per our handbook good practice > https://docs.gitlab.com/ee/development/fe_guide/style/javascript.html#export-constants-as-primitives

Prefer exporting constant primitives with a common namespace over exporting objects.

Screenshots or screen recordings

There is no UI/UX change in this MR.

How to set up and validate locally

n/a

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #370864 (closed)