Support for arbitrary categorical outcomes

[kongzii]

Currently, all markets on Omen (created by Olas or our Replicator) are categorical, but the categories are [Yes, No], so we consider them as binary markets (True, False outcomes).

However, most markets on Seer are truly categorical:

But there are also some binary (although in a different order of outcomes, pay attention to indexes there! 😄 ):

If we truly want to support Seer and make Presagio a bit more fancy, we need to add support for truly categorical markets at least (and later on also scalar markets...)

This is harder than it looks like because at many places in code we do stuff like from_bool, outcome: bool, or all agents are producing p_yes instead of the outcome: probability pairs... so it needs a lot of thinking about how to structure PMAT and how to make current agents still usable and at least one new agent to test this out.