feat: add surveys / polls

[fernandolguevara]

#65

@fiatjaf what number could we use for this nip ?

[fiatjaf]

41 I guess.

But this NIP is confusing to me. Why do relays have to know about the status of a poll? I guess this could use the parametrized replaceable events thing.

Also why are you defining t tags, p tags and other stuff on the poll answer event? These could be used, but they shouldn't be specified by this NIP, unless I'm missing something.

[fernandolguevara]

@fiatjaf t and p tags are on the json examples just to show how this feature extend kind 1 events.

I will check if it is possible to use parametrized replaceable events

[0xtlt]

I just saw this NIP proposal, I made another #148, I think we can try to merge our 2 ideas :)

So...