Add framework for UI unit tests

[steven-sheehy]

Problem

We have automation tests that spin up a headless UI to test, but they're heavyweight and tests aren't always added at the same time as the PR that adds the feature. We should have smaller, focused unit tests included in every PR.

Solution

• Use an existing testing tool/framework
• Use explorer as inspiration as it does this already with vue
• Test individual vue components to ensure given a certain input a certain output is rendered
• Use mocks or stubs for backend calls.
• Add one or two test examples that showcase this approach.
• Future sprints and PRs will slowly increase the unit test coverage.

Alternatives

No response