Multiple dependencies to Fabric Samples

The current repo contains three references to the Fabric Samples repository.

- `go.mod`: which is via the sample of the [asset-transfer-basic](https://github.com/hyperledger/fabric-private-chaincode/tree/main/samples/chaincode/fabric-samples/asset-transfer-basic). It refers to commit `84f9ba1dc4ec`.
- `samples/deployment/test-network`: which contains [setup.sh](https://github.com/hyperledger/fabric-private-chaincode/blob/main/samples/deployment/test-network/setup.sh#L26), a script to clone fabric samples repo to use the test-network. It refers to commit `50b69f6`
- `integration/deployment_test.sh`: which clones the latest version of fabric samples to package and install the `asset-transfer-basic/chaincode-go` during the [integration test](https://github.com/hyperledger/fabric-private-chaincode/blob/main/integration/deployment_test.sh#L28). It refers to the latest commit during test execution.

This inconsistency may render in potential issues when playing, building, and testing FPC. We may want to explore ways to keep these dependency in sync.