Cis2

[MilkywayPirate]

Purpose

Address #216 by introducing a Cis2Client for interfacing with CIS2 compliant smart contracts.

Changes

• Introduced a Cis2Client for interfacing with a CIS2 compliant smart contract
• Support for deserializing a smart contract update transaction
• Fix a bug where smart contract invocations included the parameters in a serialized format where the length of the parameter was prepended (as is the case for smart contract updates/initializations)
• Fix such that reject reasons are being parsed into the resulting AccountTransactionDetails object.
• Snapshotted the version as it was not done since the last release.

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.

[shjortConcordium]

I think it could make sense to have examples for some of the CIS-2 client methods, like we do for in the JS SDK?
https://github.com/Concordium/concordium-node-sdk-js/tree/main/examples/nodejs/cis2