[EPIC, Sim] Integrate subgraph prediction into sim trading

[KatunaNorbert]

Target Make money trading against previous prediction signals

To dos

• [x] make sims fetch necessary prediction data to be used for trading simulation #1262
• [x] make it easy to specify inside ppss.yaml what prediction data to be used by trader #1262
• [x] integrate prediction signals into sim engine and make it possible to trade agains those #1263
• [x] fix duckdb tests are failing on the github actions test #1303
• [x] get contract ids from duckDb instead of subgraph to reduce subgraph load and allow engine to run on existing data if subgraph is unavailable #1310
• [x] mock subgraph data inside tests #1313
• [ ] test the e-e flow
• [x] update readme and docs accordingly #1316

[KatunaNorbert]

At first step we will add the new chain feed prediction on top of the already existing code and just easily switch between the 2 prediction sources by using a use_own_model flag inside ppss.yaml as: `# predict price direction

    if ppss.sim_ss.use_own_model:
      prob_up: float = model.predict_ptrue(X_test)[0]  # in [0.0, 1.0]
    else:
      prob_up: float = <<get chain feed prediction>>

`