Resolve "Import/export in SQLite format"

See merge request !393

Also, no need for `liftBase` in `getCorpusSQLite`.

Resolve "Implement temporary file storage"

See merge request !392

In an attempt to make the TSV parser more lenient for the absence of the
forms column, I have used NoHeader in the `decodeWithP` call, but that
caused the first line of the TSVs with a header to be interpreted as
terms, which is not what we want.

We would like to use IPC communication during testing, so that we
can leverage indpendent test runs. However, the implementation turned
out to be buggy in the now-unmaintainted `nanomsg`.

Concurrency is a good way to trigger any interleaving bug.

They can be enabled with `GGTX_LOG_LEVEL` during tests.

The bug is elsewhere.

This commit extends the timeout around the `readTChan` in the ping-pong
test to 60 seconds, mostly to account for CI slowness and to rule-out
potential source of flakyness.

The calls to `threadDelay` have been removed, as they doesn't seem to
affect the overall stability of the test (at least locally) -- the
point of the exercise is trying to expose as much as possible potential
problems which might be masked by active waits.

Relax a bit moveChecks to account for shared nodes

Closes #455

See merge request !398

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.

We can use it to implement the specific case for `serveWorkerAPI`, while
giving the user the ability to do things in the monad `m`, like
introduce specific logging.