[EPIC] Switch to USDC

[trizin]

Code Changes

• Change web3_pp OCEAN address and token to USDC #1750
• Update OCEAN faucet README for stake token #1756
• Add USDC addresses into address.json in oceanprotocol/contracts #1755
• Update subgraph functions and calls to filter out Paused prediction contracts, everywhere that calls predictContracts #1752
• Set prediction token address to USDC in web3_pp
• Check and clean up remaining OCEAN instances in
• Prepare a guide on how to migrate old clients

Note: Updated related README files in each step

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Warning

NEXT STEPS WILL BREAK OLD CLIENTS

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Deployment

First do on Testnet, then on Mainnet:

• Ensure all tests green.
• Calculate and set the weekly target consumption rate in USDC for dfbuyer
• Call pausePredictions on existing contracts to stop predictions.
• Deploy 10 new pairs on the network (with web3_pp.prediction_token set to USDC)
• Deploy updated pdr-backend components to our Kubernetes cluster
  • Deploy trueval
  • Deploy dfbuyer
• Test all pdr-backend components are working.
• Test frontend.