sdk(test): [NET-1385] Use DATAv2 instead of TestToken

[teogeb]

The DATAv2Abi.json and DATAv2.d.ts files are copy-pasted from https://www.npmjs.com/package/@streamr/data-v2 (v1.0.3)

• jq '.abi' ./artifacts/contracts/DATAv2.sol/DATAv2.json > DATAv2Abi.json`
• cp ./typechain/contracts/DATAv2.d.ts . and manually added two comment lines to the top of the file

Future improvements

• We could maybe import these directly form @streamr/data-v2 or from a new unified contract package (see ETH-7999)
  • currently all contract artifacts are manually copy-pasted
  • if we import from other packages, it is to good to extract only the ABI part of the JSON (e.g with jq like done here) to reduce the file size significantly (~48K -> ~20K)
• We can simplify test token handling in operatorContractUtils

[linear]

NET-1385 Use Data token instead of TestToken in client