feat: load usage data into editor

[lars-reimann]

Closes #494.

Summary of Changes

Add way to upload usage data into the editor.

Screenshots (if necessary)

Import Dropdown

Import Dialog

Testing Instructions

1. Click on the import dropdown in the menu bar
2. Click on the "Usages" entry
3. Click on the dropzone
4. Select a usage file
5. Click submit
6. Ensure no errors are thrown

[github-actions]

MegaLinter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ CREDENTIALS	secretlint	yes		no	3.21s
✅ GIT	git_diff	yes		no	0.01s
✅ TYPESCRIPT	prettier	6	0	0	1.6s

See errors details in artifact MegaLinter reports on CI Job page
Set VALIDATE_ALL_CODEBASE: true in mega-linter.yml to validate all sources, not only the diff