This commit removes the previous test cases which excised the proper
validation of graph announcements on the network. As full generation of
the authenticated messages has not yet been implemented, these tests
aren’t currently applicable.
In a future commit, these tests will be replicated on the new discovery
package which will handle producing the channel proofs and also fully
validating them.
This commit separates out the ChannelID into a new file, with
additional helper methods for conversion and formatting. With this
commit, the struct is now more general purpose and can be used in the
new routing package, database, and other related sub-systems.
