Migrate dApp examples to use generated smart contract clients

[limemloh]

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)
• [X] sponsoredTransactionsAuction (This already uses ccd-js-gen but with some workarounds related to the webwallet, which are not needed anymore) https://github.com/Concordium/concordium-dapp-examples/pull/55
• [ ] Web3ID issuer frontend
• [ ] wCCD example
• [ ] voting example
• [ ] eSealing example
• [ ] nft-minting example
• [ ] piggy-bank example
• [ ] wallet-connect-test-bench