(chore) Separate linting and formatting concerns

[denniskigen]

Requirements

• This PR has a title that briefly describes the work done, including the ticket number if there is a ticket.
• My work conforms to the OpenMRS 3.0 Styleguide.
• I checked for feature overlap with existing widgets.

Summary

Our current setup is running Prettier as a part of ESLint. These are two separate concerns that should be handled separately by different tools.

This PR removes eslint-plugin-prettier and eslint-config-prettier from our linting config as recommended here and here. I've also separated ESLint concerns from Prettier so that ESLint doesn't handle both. The recommended modern approach treats Prettier and ESLint as separate unrelated tools.

I've also removed the prettier script from the root-level package.json to the lint-staged config so that lint-staged runs Prettier after ESLint.

Screenshots

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Issue

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Other

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[ibacher]

I'm surprised this involved no changes to the actual code!

[denniskigen]

That's because I've turned most everything off to keep the diff tight.