Enable Olas agents to use 'better' prediction mechs

[evangriffiths]

• Which mech service mechs are olas agents using?
• Are they using one any which has the prediction prophet mech available?
• If not, we should deploy our own mech service with this mech tool, and make it available for them to use

The motive is that we recently observed that olas agents are losing money. Presumably this is because they are using bad mechs (because our PP agent is making a profit). By improving the accuracy of Olas agent predictions, we should improve market predictions overall.