Add end to end decode examples

[jsdw]

It'd be great if we had a couple of example binaries in this folder which use the absolute minimum of code to decode a specific block or storage entry from an RPC node.

Perhaps we'll end up with two separate commands/binaries like:

• decode_storage --block 1234 --pallet System --entry Accounts --types types/polkadot_types.yaml --url wss://rpc.polkadot.io
• decode_block --block 1234 --types types/polkadot_types.yaml --url wss://rpc.polkadot.io

These commands wouldn't do anything clever or have great error handling or whatever; just print basic information on decoding. To see the required logic we can look at the more complicated subcommands in https://github.com/jsdw/polkadot-historic-decoding-example/tree/main/src/commands.

[Polkadot-Forum]

This issue has been mentioned on Polkadot Forum. There might be relevant details there:

https://forum.polkadot.network/t/decoding-old-and-new-blocks-and-storage-entries-in-rust-october-2024-update/10276/1