Separate "New Talk" and "Suggest Talk"

[locks]

"New Talk" would be the speaker themselves would suggest a new talk they want to give.
"Suggest Talk" would be a speaker/anon would suggest someone else to present a talk.

I think it might be worthwhile to separate the two in the domain model, since they're slightly different things with slightly different lifecycles. A suggested talk could be approved/scheduled, or rejected (either by us or by the suggested speaker).