Part 3/3 for #14435
Won't be merging in until all parts are approved.

Changes made

• Updated test helpers and top-level app components to make it easy to mock out implementations for specific providers
• Added test for WorkspacePage to ensure that page navigations from there to the main workspace page resolve properly and account for the organization name

Bonus

• Cleaned up a ternary that wasn't needed

Notes

• Really wanted to add tests for the workspace pages filter (since we don't have any yet), but getting that part of the code into a reproducible state for tests is going to be a doozy. I tried for a little bit but ended up giving up. Think it's better to punt that until we can work on finally work on cleaning up all the logic surrounding that part of the codebase