This will allow us to move away from storing this database centric
setting as related to the server.

https://bugzilla.redhat.com/show_bug.cgi?id=1389821

This also exposes a new method, `#active_excludes`, to retrieve
the current excludes being used by pglogical. This will pull
the list of tables directly from the pglogical tables in the
database rather than using an intermediate list of settings
related to the server.

https://bugzilla.redhat.com/show_bug.cgi?id=1389821

We can't use the instance methods with the queue because this is
not an ActiveRecord object.

https://bugzilla.redhat.com/show_bug.cgi?id=1389821

https://bugzilla.redhat.com/show_bug.cgi?id=1389821

This is no longer needed because the exclude tables are not stored
in the global Settings anymore.

https://bugzilla.redhat.com/show_bug.cgi?id=1389821

…ances

This means that `MiqPglogical.new.refresh_excludes` will not change
the excluded tables back to the default, but will leave them as
they currently are.

https://bugzilla.redhat.com/show_bug.cgi?id=1389821

Because we have removed the excludes from the settings.yml file
we should remove the changes made in the database.

This will leave current installations of pglogical in the same state
they were in (we will read the excludes from the pglogical tables),
but will reset new installations created when moving from rubyrep
to pglogical.

https://bugzilla.redhat.com/show_bug.cgi?id=1389821