The test Hot Rod client in the server module is slow

ClientHandler.getResponse() has had a TODO comment from the beginning

// Very TODO very primitive way of waiting for a response. Convert to a Future

If the server does not process the request synchronously, which is quite common, ClientHandler.getResponse() will wait at least 100ms. HotRodFunctional.testBulkGet() inserts 100 entries 1-by-1, and it always takes more than 8 seconds in CI.