Migrate dApp examples to use generated smart contract clients

[Emil Holm Gjørup]

Our various dApp examples should use generated smart contract clients (ccd-js-gen).
This is to track the task of doing so.

This cannot be done until the web-wallet API supports web-SDK v7.

The relevant dApps in no particular order:

• low-code-nft-marketplace
• sponsoredTransactions (The tutorial in the developer documentation will need to be updated as well)
• sponsoredTransactionsAuction (This already uses ccd-js-gen but with some workarounds related to the webwallet, which are not needed anymore) Concordium/concordium-dapp-examples#55
• Web3ID issuer frontend
• wCCD example
• voting example
• eSealing example
• nft-minting example
• piggy-bank example
• wallet-connect-test-bench