Dispute snapshoted arbitration config

[Corantin]

Contracts

• Store the arb setting version on the proposal
• Consider snapshoted arb setting when ruling and separate submitterCollateralAmount
• Remove limitation to change arb settings during dispute

Subgraph

• PoolParamUpdated -> CVParams udpated and ArbSettingsUpdated with a version and new entity when change
• DisputeCreated -> Add arb config to proposal entity

Frontend

• Remove limitation to change arb settings when ongoing dispute
• Fetch arb config with new entity
• Dispute modal: Fetch config from the dispute