Remove allow-newer:*, allow-older:* in cabal.project file and instead
list these explicitly. This is a big step for managing dependencies.

- Re-enable orphan warnings that were manually disabled in many modules
- Remove non-Haskell files that were just sitting in the source tree
- Remove modules that were not called from anywhere
- Remove unused dependencies

This is not exhaustive by any means. In particular, some more weeding out
can be achieved by looking at individual functions and even branches of
functions. Weeder can help with that.

- 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

This commit maps the "Publish" action inside CodiMD/HedgeDoc to the
share URL feature.

While doing this, I have also fixed a bug in the current implementation
of ThrowAll (formerly named `throwAll'`).

It integrates servant-routes which allows to list and export the
server backend routes.

This commit moves `GargConfig` and the other config-related
data structures back into gargantext, so that they can be edited
and expanded without needing to worry about the prelude project.

This commit extends the reverse proxy for the microservices so that it
would serve a custom `/config` file which would contain the correct
baseUrl to initialise the websocket connection correctly.

Still needs to fix some hardcoded URLs. The problem with websockets is
that they use the first URL fragment to determine the documentId,
therefore we cannot proxy to `http://localhost:8009/notes/<frameId>`
because the underlying WS connection will use `noteId=notes`, which is
wrong.