this PR puts sync stuff in the bemo worker, and sets up a temporary
dev-only page in dotcom for testing bemo stuff
### Change type
- [ ] `bugfix`
- [ ] `improvement`
- [x] `feature`
- [ ] `api`
- [ ] `other`
### Test plan
1. Create a shape...
2.
- [ ] Unit tests
- [ ] End to end tests
### Release notes
- Fixed a bug with...
Right now it's fairly easy to encounter a situation when a tab coming
online wouldn't recognise that the connection can now be reestablished
for a while. This PR cleans up reconnection logic, reenables tests, and
makes sure we get online as robustly as possible.
### Change Type
- [x] `patch` — Bug fix
### Test Plan
1. Check that reconnection works as expected
- [x] End to end tests
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Co-authored-by: David Sheldrick <d.j.sheldrick@gmail.com>
