Get some more privacy around the environment passed around in Action.
This wraps the Env type alias in a discriminated union to generate type
errors on usage, then moves direct accesses to Env and wraps the original
usage in an API or moves the code to the Env module.

Env DMap via a Generic in the Set case of Action. So this limits usage
of the SetKeyVal type alias to the Types module momentarily to limit
exposure of the Generic that packages key-value pairs for insertion
into the DMap.

This moves the access to the Set case of action exposing SetKeyVal into
Types.hs; the wrapper may move again, but the caller will be insulated.

This splits it up into SNetworkId and SSocketPath and removes the old
User constructor. A sweep is done and accessors in Env likewise changed.

This monomorphises Action's Set case in order to remove the last
dependencies on Setters.Tag via SetKeyVal. The Setters file is
removed from the tree and the cabal file as well.

There are no callers outside Env.

This trades in the Named case of Store for the various cases of Name.
getName & setName are bypassed in favour of get/set of the Store
directly.

They're not abstracting much as the approach is from a different
direction. They don't save much typing, either. It saves a few
lines & saves some module dependencies.

Searching revealed no use cases of the LoggingLayer case. This reduces
the number of distinct cases needed to remove from the Env DMap.

It largely represents a sort of individual state variable, so the
corresponding dmap entry in Env is replaced with an additional
record field. Accessors replace the usage of the case of Store.

A pair of get & set accessors is coupled with a record field in Env
to replace the usage of the Store case in the Env DMap.

This adds an Env record field to replace the Genesis DMap entry and
sweeps uses of the Store case/constructor replacing with accessors.

The Env accessors were duplicating a lot of code, so this just does
some lambda lifting across the minor differences. The subroutines for
the shared code are likely worth using to replace the accessors
outright given an audit of record field names for name clashes &
renaming for more brevity.

It's replaced with a record field in Env and accessors to get & set it.

I inadvertently introduced hlint warnings in this branch by dint of some
cut & paste of unnecessary $'s. This should hopefully dispose of them,
but I'll have to find out how to run hlint in the build system to be
sure.

This replaces the SNetworkId case of Store with a monomorphic NetworkId
record field of Env.

This folds the socket's FilePath into a record field of Env.

This replaces the KeyName case with a monomorphic Map in Env. Helpers
are set up to help subsequent wallet & thread patches. Some testing will
be needed to ensure there's no impact on Aeson's JSON formatting.

This removes the ThreadName constructor from Store and replaces it with
a monomorphic Map in the Env structure and accessors.

This removes the use of the WalletName type alias, WalletName
constructor, and the entire Store module, moving its remainder to
Script/Types. At the end of this, the use of the Generic DMap is also
removed altogether in Env. The cabal file is updated to reflect the
removal of the Store.hs source file.