[Example] Authorize preimage and store

[bkontur]

TODO

• Create authorize_preimage_and_store_papi.js (copy of authorize_and_store_papi.js)
• Instead of TransactionStorage.authorize_account we want TransactionStorage.authorize_preimage
• we need to submit store(data) as unsigned transaction, so no signer (anybody can submit)
  • Investigate how to do it with PAPI: export async function store(typedApi, signer, data) { and function waitForTransaction(tx, signer -> tx.signSubmitAndWatch(signer)
• add it to the examples/justfile
• add it to the .github/workflows/integration-test.yml