[Sim, ppss] Define average stake amount and accuracy, *per feed*

[trizin]

Background / motivation

Status quo: ppss enables the user to set a single average accuracy (of other traders) overall. This is the setting predictoor_ss.sim_only.others_accuracy. Same for stake; setting is others_stake.

Datapoint: average accuracy makes a huge difference to profitability of predictoor. Eg value of 50% makes it easier to be profitable, value of 53% makes it much harder, 56% harder yet

Datapoint: in practice, average accuracy is quite different per feed. On some feeds it might be 51.8%, on others 53%, on others 56%. These accuracies tend to be fairly stable over the weeks, and slowly increasing due to an arms race among predictoors.

The datapoints above lead to a problem: when we simulate, if we change the feed, we have to update the single average accuracy to be reflective of the given feed we're predicting. It's a pain.

Towards a solution

We need to enable users to define average stake amount and accuracy, per feed. This will help sim give more realistic profitabilities for prediction bots.

TODO

• ppss.yaml enables user to define average accuracy and stake amount, per feed. Add unit tests accordingly
• reflect this upwards in the code to the level of the simulator

[trizin]

#1257 is a better solution, don't think is needed anymore. Closing...