Add support for metadata hash verification.

[gianfra-t]

Context: Support for new Ledger App.

Closes [No ticket related, small change].

Following this guide, here we add the relevant code for the runtime to accept the verification of the metadata that was used for signing the extrinsic.

Note: the command to build the node for production now is cargo build --release --features metadata-hash.

It is important to note given that is not clear on the guide, that the environment variable required when building with this new feature (RUNTIME_METADATA_HASH) is set by the build script when the flag metadata-hash is used. See here.

[gianfra-t]

@pendulum-chain/devs I am not sure if this change will break existing integration of our services (and external ones), since now the runtime is expecting an extra byte that will flag if the sender of the extrinsic wants to verify the metadata or not (see flags here). I couldn't find this information on the Polkadot.js API, I would assume that by default this flag is set to not verify.

[ebma]

I am not sure if this change will break existing integration of our services (and external ones), since now the runtime is expecting an extra byte that will flag if the sender of the extrinsic wants to verify the metadata or not (see flags here).

Let's just see how it goes on Foucoco. I think we don't need to explicitly define it but if we do, we can just define it in pendulum.js and upgrade the dependencies that are using pendulum.js already. Then it should be included automatically.

Once this is merged we also need to change our Gitlab release pipeline to include the new --features metadata-hash flag by default. The pipeline will compile the wasm runtimes and put it into the Github releases after all.