Before we were repeating the same code to initialise all the different
loggers. This commit introduces two stock loggers called `ioStdLogger`
and `monadicStdLogger` which can be reused many times.

It also allows the `GGTX_LOG_LEVEL` to take effect during `readConfig`,
so that the `startupInfo` would show up the correct information.

This commit correctly propagates the correct `LogConfig` in all the
places where we were just defaulting to log everything, and this allows
us to silence debug logs in tests, unless we want them.

With this data structure, we can tell what goes into SQLite and what
can (in the future implementation) be read from it.

I fixed those warnings that were easy to fix: redundant imports, unused
variables, etc. (I might have missed some though)

The warnings I deliberately left for now are:
* In `Test.API.UpdateList`: Incomplete pattern matching (we would need
  to think a bit about error handling to fix this)
* In `Test.Utils`: `traceShowId` remains in code (we would need to think
  a bit about proper logging to fix this)

Start worker in tests

Now everything is in Core/Config

I moved HasConfig to Core/Config instead of it being in Database.Prelude

Also, changed exceptions to safe

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.

Get rid of that TVar completely.

This commit adds a `panicTrace` function to be used as a drop-in
replacement of the `panic` function, with the difference that we
wrap the error in a `WithStacktrace` error, to be later caught
and logged.

Also, some fixes to NodeStory (it inserts ngrams when saving node
story, when they don't exist).

Basically, Gargantext.Prelude exports all of Protolude now.

Tests were written with a very flat module hierarchy which made them
a bit confusing to navigate. This commit moves everything under a common
`Test.*` hierarchy.

We now require CoreNLP listening on port :9000. We will have to find
a way to spin that up in CI as well.