[Vue 3] Investigate ActivityTable test failure

[jeffsmohan]

After upgrading to Vue 3 with the Vue 2 compatibility layer, the src/components/ActivityTable.spec.js tests are failing. This is happening because we can no longer test the BootstrapVue-based table component's contents. This can't be easily fixed without migrating away from the Vue2-only bootstrap-vue or refactoring the component so the table contents are more testable (say, each cell getting its own Vue component).