Publish velocity commands from RamseteCommand to NetworkTables

[calcmogul]

Is your feature request related to a problem? Please describe.
When RamseteCommand doesn't work out of the box, you need to be able to plot the pose setpoint, pose estimate, velocity commands, velocity measurements, and motor voltages to figure out what's going wrong. RamseteCommand has access to the pose setpoint and velocity commands, but doesn't expose them.

Describe the solution you'd like
The data mentioned above should be available on NetworkTables for live plotting with Glass.

[rzblue]

How would we want to do this/where should we put the values? We probably don't want to have them published to a static table since you can create multiple RamseteCommands.

We could have the option for the user to select a root table, maybe only publish if they specify that option?

[Starlight220]

Since RamseteCommand is Sendable (via CommandBase), I think it'd be natural to override initSendable and publish the data there.

[rzblue]

The only issue there is that any composition is going to mess that up.

[sciencewhiz]

Is there already something to borrow from the sendable richness PR?

[Starlight220]

The setpoints can be retrieved using the velocity-accepting lambda ctor.