chore(gatsby) Convert get-value-at to typescript

[martijnjanssen]

Description

Convert utils/get-value-at and __tests__/get-value-at to Typescript

Related Issues

Related to #21995

[blainekasten]

This looks great to me, let's merge it!

Thank you so much for contributing to our TypeScript refactor! We have more work to do and we would love to have you stay involved in our transition. Please submit more PRs! 💜

[gatsbot]

Holy buckets, @martijnjanssen — we just merged your PR to Gatsby! 💪💜

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