Allow using AppElements as a type

[aslakhellesoy]

Description

Using AppElements as a type in a function parameter gives the error TS2749: 'AppElements' refers to a value, but is being used as a type here. Did you mean 'typeof AppElements'?

Motivation & context

I want to use it as a type

Type of change

• Refactoring/debt (improvement to code design or tooling without changing behaviour)
• Bug fix (non-breaking change which fixes an issue)

Note to other contributors

Follow the pattern in src/renderer/api/index.js if new classes and types are added to the API

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.