Observations table for each target should list the site or cadence name

[captain-exoplanet]

Currently, the Observations tab for each target contains a table listing the facility, when each observation request was created, the status, whether the request has been scheduled, and the number of saved data.

It would be desirable for this table to also list the site at which each observation request is scheduled/was obtained, and/or the name of the cadence request to which the request belongs.