We eventually want to switch over to NdbNote instead of NostrEvent. To
facilitate this, the plan is to eventually make NostrEvent an alias of
NdbNote. For this to work, let's make sure the NostrEvent extensions are
implemented on NdbNote.
We will likely switch away from string properties as well, but for now
we will try to emulate as much as possible to make sure everything is
working first.
William Casarin