[UI v2] feat: Adds @tests alias for easier access when writing tests

[devinvillarosa]

Importing re-usable testing mocks can be confusing by using relative pathing. This PR adds an alias to make it straightforward in importing re-usable mocks in our tests

Checklist

1. Creates a path alias @tests.
2. Updates tests to use import { server } from '@tests/mocks

• This pull request references any related issue by including "closes <link to issue>"
  • If no issue exists and your change is not a small fix, please create an issue first.
• If this pull request adds new functionality, it includes unit tests that cover the changes
• If this pull request removes docs files, it includes redirect settings in mint.json.
• If this pull request adds functions or classes, it includes helpful docstrings.

[desertaxle]

Nice!