Group Import history - Page size not persisted

Problem to solve

The Group Import history page has a page control that allows the user to select whether they want to see 20, 50, or 100 entries per page.

However, with each visit to this page (or a refresh), this page size is reset to 20 and the user has to reselect the page size again.

Screenshot

Proposed solution

As a first iteration, persist the selected page size in local storage so that the user doesn't have to keep selecting the desired page size.

Future iterations

Persist this preference in the user profile, so that it is preserved across different devices.

Implementation plan

We're setting perPage size in data in app/assets/javascripts/pages/import/bulk_imports/history/components/bulk_imports_history_app.vue. To persist it to local storage please use our wrapper app/assets/javascripts/vue_shared/components/local_storage_sync.vue - you can see examples of it's usage across codebase. Please use gl-bulk-imports-history-per-page as key and put it in constant on top of the file

You might need to update relevant test in spec/frontend/pages/import/bulk_imports/history/components/bulk_imports_history_app_spec.js and stub local-storage-sync component with dummy one for most of the tests

Update tests accordingly :)