Comment 1 for bug 1854850

IndexedDB shared worker communication service implemented here.

Branch includes a second commit to implement the org unit caching described in bug #1848550. The second commit should only be merged if #1848550 is merged.

https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/berick/lp1854850-ang-indexeddb-coms