Expose more ChannelDetails fields

[tnull]

In #56, we'll reduce the set of exposed fields in ChannelDetails to a minimum.

For example, we won't expose {inbound,outbound}_scid_aliases. We should figure out if and how we need to expose them (e.g. for LSPS integration), or if we just can leave as is and handle everything internally for the user.

[tnull]

In #165 more properties were added to the exposed ChannelDetails while we still don't expose SCID aliases, I consider this issue addressed for now until we find a reason to expose even more fields.