ENG-4659 feat(portal): set up hydration boundary (#898)

- Adds in the HydrationBoundary in the providers.tsx -- this enables the
partial hydration pattern referenced in
#885
- Once this wraps Portal via the providers we can partially hydrate as
long as the queryKey matches server + client side. This won't have any
bearing on our client-side only hooks such as in modals but enables the
hydration pattern where loaders are available
- The HydrationBoundary ensures that our client-side cache for each
query (where loaders are available) starts with the same data that was
fetched and rendered on the server
- Note: This re-opens PR #888 into `feature/graphql-migration` instead
of onto `main`