CE-1941: replace error pages with common components
- Migrates 404 pages to use common error page
- Migrates error boundary to use common error boundary (updated version has fixes)
- adds a test route at
/error-test
to trigger the error boundary (reminder: when running in dev mode locally, you must dismiss the React overlay/modal by clicking the "x" in the upper right in order to see it)
Closes CE-1941
Edited by Christina Jenks