v2.0.0-beta.18

Changelog:

• Separate State management and Subscription management
• Change state persisted on storage
• Change subscriptions persisted on storage
• Track Relayer published and received JSON-RPC history
• Add versioned keys for storage persisted data

Client breaking changes:

• state persisted will be different than previous versions however the versioned keys will avoid any conflicts with old state but the old state will never be cleared by the client

Protocol breaking changes:

• expiry for sequences (pairing and session) used to be defined in milliseconds and now it's defined in seconds instead (this will cause incorrect expiries when clients of previous version connect to newer versions)
• wc_pairingApprove and wc_sessionApprove no longer share the topic on the payloads when approving (this will NOT break interoperability since Javascript clients weren't using this parameter from the payloads)