v0.15.0

Added

• implement variant of subscription that returns finalized storage changes - #237
• implement session handling for unsubscribe in subxt-client - #242

Changed

• update jsonrpsee #251
• return none if subscription returns early #250
• export ModuleError and RuntimeError for downstream usage - #246
• rpc client methods should be public for downstream usage - #240
• re-export WasmExecutionMethod for downstream usage - #239
• integration with jsonrpsee v2 - #214
• expose wasm execution method on subxt client config - #230
• Add hooks to register event types for decoding - #227
• Substrate 3.0 - #232