Upgrade polkadot v1.19.1

📝 Release Notes

• Upgrade Polkadot SDK

• Upgrade Rust

• Upgrade Benchmark

  • ⚠️ Note: The write storage benchmark (but not the read) will fail if the number of keys is less than the batch size with Error:** Input("Empty input is invalid"). I don't know if is intended or not, this is a remainder to investigate and open a PR upstream if necessary. Little impact in production, where this should be run on a snapshot of the live chain with a lot of keys.

• Uprade doc generation with new metadata version

• Fix Clippy Warnings

• Run Benchmarks

• Run Metadata

• Upgrade Subxt