Code: Moved layer panel to proper folder structure

[barklund]

Context

This is just step one of refactoring the layer panel. Decided to do this in a single PR to make change sets more obvious.

User-facing changes

None

Testing Instructions

• This is a non-user-facing change and requires no QA

Checklist

• This PR addresses an existing issue and I have linked this PR to it in ZenHub
• I have tested this code to the best of my abilities
• I have verified accessibility to the best of my abilities (docs)
• I have verified i18n and l10n (translation, right-to-left layout) to the best of my abilities
• This code is covered by automated tests (unit, integration, and/or e2e) to verify it works as intended (docs)
• I have added documentation where necessary
• I have added a matching Type: XYZ label to the PR

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Partially address #11576

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