Drops the `Settings` member from `AbstractComponent`, moving it from the
base class on to the classes that use it. For the most part this is a
mechanical change that doesn't drop `Settings` accesses. The one
exception to this is naming threads where it switches from an invocation
that passes `Settings` and extracts the node name to one that explicitly
passes the node name.

This change doesn't drop the `Settings` argument from
`AbstractComponent`'s ctor because this change is big enough as is.
We'll do that in a follow up change.