Add a CIS4 client to the node/web SDK

[Aleš Bizjak]

Task description

The client should be like a CIS2 client for CIS4 contracts.

See https://github.com/Concordium/concordium-rust-sdk/blob/main/src/cis4.rs#L83 for a draft version of the Rust one.

Do note that at this point some details in CIS4 might change since the integration with the wallets is still being done.

Additionally the CIS4 client should be expanded with support for storing credentials, i.e., there should be support for serializing the "additional_data" for the registry contract that can be used for storing credentials.

Sub tasks

• Implement CIS4Contract client
• Add unit tests
• Add examples
• Documentation