Convert sink components to use typetag

[bruceg]

This is follow-up work to converting the transforms to use typetag. The required steps (for sinks) are:

• Converting the SinkOuter.inner field from the Sinks enum to a Box<dyn SinkConfig>.
• Manually implementing Configurable for Box<dyn SinkConfig>.
• Adding the typetag macro wrapper to trait SinkConfig.
• Adding the typetag macro wrapper to all impl SinkConfig for … blocks.
• Moving the component description from enum Sinks into the individual component config struct's configurable_component macro.

Once both sources and sinks are done, there is some bits in the config macros that can be cleaned up, in particular in fn TypedComponent::get_component_desc_registration.