It also:

* Amends tests for policy checks status code changes
* Fix a bug in isNodeReadOnly
* Adds a function to return all the nodes ids for the published
  nodes. Next we need to modify `findShared` & co to make sure that
  published notes will show somewhere in the users' tree.

Now this query accounts correctly for recursive children.

It also:

* Adds basic publish/unpublish works
* Add Move API tests scaffolding

Now a `NodeNodePoly` stores a typed `NodeNodeCategory`, we can use
to enforce invariants and making lookups more efficient.

This commit makes this function private to the `Table.NodeNode` module
as it's fairly low-level, and it doesn't let us embed logic to ensure we
are creating a valid node2node relationship. Better use one of the other
specialised functions.

This commit removes the `InsertDB` typeclass, an indirection which
wasn't very useful as it was being used in exactly one place in the
whole codebase (i.e. the share code).

Talking about share, this commit refactors things ever so slightly so
that we have a dedicated `shareNode` operation rather than using the
low-level `insertNodeNode`.

This commit splits the old `NodeAPIEndpoint` type into three;

* `NodeAPIEndpoint`, which will also contain the freeze endpoint;
* `AnnuaireAPIEndpoint`, which is the plain old node API without extra
  features;
* `CorpusAPIEndpoint`, which will also contain the publishin endpoint.

This split ensures that we don't add endpoints which do not belong to
all three categories, like before.

Furthermore this adds a public nodes SQL queries.
It also adds tests for getUserRootPublicNode

This allows us to collect a /history/ of computing times.

The tracking is not perfect yet, as it keeps storing only the latest
available compute time. Also, there seems to be some precision loss
between that is reported by `timeMeasured` and what gets stored in the
DB.

This was because WS connection wasn't closed properly.

This commit refactors the test code ever so slightly to add a proper
type called `SpecContext` rather than anonymous pairs to carry around
the spec context/data. It also replicates the search problem around #415
via a test.

Edited the README to have a linear path to installation.
Also made scripts to run the executables without having to worry
whether they are on our path.