Feat #1202 - Fetch stake and accuracy per feed from live feeds

[trizin]

1298

• ppss parameter to toggle "fetch stake and accuracy per feed from live feeds"
• Function to fetch stake and accuracy and tests

[KatunaNorbert]

Good quick solution for calculating this 2 values, should offer much accurate environment for predictoor simulations. My only comment is that the periods for calculating this values inside the accuracy endpoint are fixed, so this could become less relevant depending on the period you are running your simulations on. Ex: for 5m fields the accuracy and stakes are calculated over the last week, but the simulation could be run over the last month