This commit refactors the common pattern `bracket init deinit use` in
`withNotifications` in `drivers.hspec.Main`, so that `withNotifications`
in atomic and the user doesn't incur in the pattern of using the init
and deinit functions independently from the `bracket`.

To be faithful about what I preach, we should do the same for
`startCoreNLPServer` and `stopCoreNLPServer`.

This commit tightens up the public API exposed by the Dispatcher,
for similar reasons as we had for the CentralExchange.

This commit tigthen the public API for the `.CentralExchange` module,
so that it's clear which are the exported (public) functions, and
we do not leak the transport layer used by the central exchange

- edit bin/update-project-dependencies
- fix the values of :
  - sha256sum cabal.project
  - sha256sum cabal.project.freeze
- nix-shell $ ./bin/update-project-dependencies
- git add -u
- git commit

Also, fix for notifications throttle delay value

Also, throttle messages to avoid flooding the client