Since we have renamed a file housing some very old code, the linter has
now run on all this code for the first time. So we gotta do some
clean-up work here to make it happy.
In this commit, we rename the existing ChannelGraph struct to KVStore to
better reflect its responsibilities as the CRUD layer. We then introduce
a new ChannelGraph struct which will eventually be the layer above the
CRUD layer in which we will handle cacheing and topology subscriptions.
For now, however, it houses only the KVStore. This means that all calls
to the KVStore will now go through this layer of indirection first. This
will allow us to slowly move the graph Cache management out of the
KVStore and into the new ChannelGraph layer.
We introduce the new ChannelGraph and rename the old one in the same
commit so that all existing call-sites don't need to change at all :)
Rename it to kv_store.go so that we can re-use the graph.go file name
later on. We will use it to house the _new_ ChannelGraph when the
existing ChannelGraph is renamed to more clearly reflect its
responsibilities as the CRUD layer.
Elle Mouton