Migrate fabric-samples to use Gateway SDKs

The following samples should be extended with gateway app samples. We don't need to have a full matrix of all samples in a languages however. Items with a 'P' are initial priorities for this work item. Add your name next to an item if you intend to pick it up.

## Higher priority

- **asset-transfer-basic** (demonstrates transaction submit / evaluate, submit error capture)
- [x] Typescript - P1 - Saptha
- [x] Java - P2 - Deepti
- [x] Go - P2 - Saptha
- **asset-transfer-events** (demonstrates chaincode events)
- [x] Typescript - P3 - Saptha
- [x] Java - P3 - Deepti
- [x] Go - P3 - Mark
- **asset-transfer-private-data** (demonstrates auto-magic handling of endorsement with private data collections)
- [x] Typescript - P4 - Saptha
- [ ] Java - P4
- [x] Go - P4
- **asset-transfer-secured-agreement** (demonstrates auto-magic handling of state-based endorsement)
- [x] Typescript - P4 - Saptha
- [ ] Java
- [ ] Go
- **off_chain_data** (demonstrates block eventing, checkpointing)
- [x] TypeScript - Mark
- [x] Java - Mark
- [x] Go
- **full-stack-asset-transfer-guide** [trader application](https://github.com/hyperledger/fabric-samples/tree/main/full-stack-asset-transfer-guide/applications/trader-typescript)
- [ ] Go
- [ ] Java

## Lower priority

- **asset-transfer-ledger-queries**
- [ ] Typescript - P5
- [ ] Java
- [ ] Go
- **asset-transfer-sbe**
- [ ] Typescript - P5
- [ ] Java
- [ ] Go

What about other samples? For example the old fabcar samples and commercial paper?

Start by comparing the completed gateway app samples under asset-transfer-basic, asset-transfer-events, asset-transfer-private-data, asset-transfer-secured-agreement, and off_chain_data. Choose an unchecked language/sample combination, including the listed full-stack-asset-transfer-guide trader application where applicable, and follow the existing sample structure. Done means the selected sample has a working Gateway SDK implementation matching its demonstrated behavior.

Written by the indexing model from the issue text.