Setup gRPC API stress test environment

We would like to ensure that the gRPC API of the node cannot be used to influence the node's ability to keep up with the network.

Before we implement any strategy, we should have a test environment where we can produce the issue.

Start by locating the node's gRPC API and determining how a stress-test environment can exercise it while the node keeps up with the network. Done means a reproducible environment exists that can generate the issue; the payload does not identify files, tests, or a concrete strategy.

Written by the indexing model from the issue text.