Issue-256 - Troubleshoot hang on streaming echo POST requests

[huntharo]

Related to #256

The actual issue ends up being a problem with the AWS ALB having an intermittent problem with these requests.

[github-actions]

📊 Rust Code Coverage Report

File	Lines	Lines Hit / Found	Uncovered Lines	Branches
/extension/src/app_client.rs	✅ 100.0%	11 / 11	0	-
/extension/src/app_request.rs	🟡 76.9%	60 / 78	18	-
/extension/src/app_start.rs	🟡 88.9%	48 / 54	6	-
/extension/src/cert.rs	🟡 74.2%	23 / 31	8	-
/extension/src/counter_drop.rs	✅ 100.0%	3 / 3	0	-
/extension/src/endpoint.rs	🟡 89.1%	82 / 92	10	-
/extension/src/lambda_request.rs	🟡 80.3%	151 / 188	37	-
/extension/src/lambda_request_error.rs	🟡 80.2%	77 / 96	19	-
/extension/src/lambda_service.rs	🟡 83.6%	133 / 159	26	-
/extension/src/main.rs	❌ 0.0%	0 / 27	27	-
/extension/src/messages.rs	🟡 86.5%	45 / 52	7	-
/extension/src/options.rs	✅ 98.4%	60 / 61	1	-
/extension/src/ping.rs	🟡 84.2%	176 / 209	33	-
/extension/src/prelude.rs	✅ 100.0%	6 / 6	0	-
/extension/src/relay.rs	🟡 57.8%	111 / 192	81	-
/extension/src/router_channel.rs	🟡 87.7%	336 / 383	47	-
/extension/src/router_client.rs	✅ 100.0%	30 / 30	0	-
/extension/src/startup.rs	🟡 80.5%	99 / 123	24	-
/extension/src/threads.rs	🟡 71.4%	5 / 7	2	-
/extension/src/time.rs	✅ 100.0%	6 / 6	0	-
/extension/src/utils/mod.rs	✅ 100.0%	31 / 31	0	-
Overall	🟡 81.2%	1493 / 1839	346	-

[github-actions]

📊 DotNet Code Coverage Report

File	Lines	Lines Hit / Found	Uncovered Lines	Branches
/src/PwrDrvr.LambdaDisp..ension/MetricsRegistry.cs	❌ 0.0%	0 / 21	21	0.0%
/src/PwrDrvr.LambdaDisp..n/HttpReverseRequester.cs	❌ 0.0%	0 / 41	41	0.0%
/src/PwrDrvr.LambdaDispatch.Extension/Function.cs	❌ 0.0%	0 / 462	462	0.0%
/src/PwrDrvr.LambdaDisp..sion/HttpDuplexContent.cs	❌ 0.0%	0 / 23	23	0.0%
/src/PwrDrvr.LambdaDisp..n/HttpReverseRequester.cs	❌ 0.0%	0 / 296	296	0.0%
/src/PwrDrvr.LambdaDisp..tension/LoggerInstance.cs	❌ 0.0%	0 / 17	17	-
/src/PwrDrvr.LambdaDisp..ension/MetricsRegistry.cs	❌ 0.0%	0 / 21	21	-
/src/PwrDrvr.LambdaDisp..ension/MetricsRegistry.cs	❌ 0.0%	0 / 71	71	0.0%
/src/PwrDrvr.LambdaDisp..on/TcpReverseRequester.cs	❌ 0.0%	0 / 194	194	0.0%
/src/PwrDrvr.LambdaDisp..ension/SetupHttpClient.cs	❌ 0.0%	0 / 33	33	0.0%
/src/PwrDrvr.LambdaDispatch.Messages/Waiter.cs	✅ 100.0%	6 / 6	0	-
/src/PwrDrvr.LambdaDispatch.Messages/Waiter.cs	❌ 0.0%	0 / 2	2	-
/src/PwrDrvr.LambdaDisp..outer/LambdaConnection.cs	✅ 100.0%	6 / 6	0	-
/src/PwrDrvr.LambdaDisp...Router/LambdaInstance.cs	✅ 100.0%	3 / 3	0	-
/src/PwrDrvr.LambdaDisp..Router/CapacityManager.cs	✅ 100.0%	51 / 51	0	100.0%
/src/PwrDrvr.LambdaDisp..Router/MetricsRegistry.cs	❌ 2.8%	1 / 36	35	0.0%
/src/PwrDrvr.LambdaDispatch.Router/Config.cs	🟡 81.4%	96 / 118	22	97.7%
/src/PwrDrvr.LambdaDisp..lers/ChunkedController.cs	🟡 88.6%	124 / 140	16	91.7%
/src/PwrDrvr.LambdaDisp..lers/DefaultController.cs	✅ 100.0%	5 / 5	0	-
/src/PwrDrvr.LambdaDisp..ollers/ResetController.cs	✅ 100.0%	8 / 8	0	-
/src/PwrDrvr.LambdaDispatch.Router/Dispatcher.cs	🟡 73.0%	333 / 456	123	66.3%
/src/PwrDrvr.LambdaDispatch.Router/Dispatcher.cs	✅ 100.0%	3 / 3	0	-
/src/PwrDrvr.LambdaDisp..dMetrics/MetricsLogger.cs	✅ 93.6%	132 / 141	9	86.7%
/src/PwrDrvr.LambdaDisp..ics/MetricsLoggerDummy.cs	❌ 0.0%	0 / 2	2	-
/src/PwrDrvr.LambdaDisp..h.Router/GetCallbackIP.cs	✅ 100.0%	8 / 8	0	100.0%
/src/PwrDrvr.LambdaDisp..omingRequestMiddleware.cs	❌ 44.6%	33 / 74	41	46.2%
/src/PwrDrvr.LambdaDisp..Router/LambdaArnParser.cs	✅ 94.6%	35 / 37	2	87.5%
/src/PwrDrvr.LambdaDisp..ter/LambdaClientConfig.cs	✅ 100.0%	18 / 18	0	100.0%
/src/PwrDrvr.LambdaDisp..outer/LambdaConnection.cs	❌ 24.6%	121 / 491	370	13.3%
/src/PwrDrvr.LambdaDisp...Router/LambdaInstance.cs	🟡 60.3%	243 / 403	160	47.5%
/src/PwrDrvr.LambdaDisp../LambdaInstanceManager.cs	✅ 100.0%	4 / 4	0	-
/src/PwrDrvr.LambdaDisp../LambdaInstanceManager.cs	❌ 34.3%	154 / 449	295	64.3%
/src/PwrDrvr.LambdaDisp../LeastOutstandingQueue.cs	🟡 67.0%	144 / 215	71	67.7%
/src/PwrDrvr.LambdaDisp...Router/LoggerInstance.cs	✅ 90.6%	29 / 32	3	83.3%
/src/PwrDrvr.LambdaDisp..Router/MetricsRegistry.cs	❌ 47.6%	10 / 21	11	-
/src/PwrDrvr.LambdaDisp..Router/MetadataService.cs	🟡 84.4%	54 / 64	10	67.6%
/src/PwrDrvr.LambdaDisp..Router/MetricsRegistry.cs	✅ 91.2%	124 / 136	12	-
/src/PwrDrvr.LambdaDisp..Router/MetricsRegistry.cs	❌ 0.0%	0 / 31	31	-
/src/PwrDrvr.LambdaDisp...Router/PendingRequest.cs	✅ 90.7%	49 / 54	5	75.0%
/src/PwrDrvr.LambdaDispatch.Router/Pool.cs	✅ 100.0%	7 / 7	0	-
/src/PwrDrvr.LambdaDispatch.Router/PoolManager.cs	🟡 89.4%	59 / 66	7	78.6%
/src/PwrDrvr.LambdaDispatch.Router/PoolOptions.cs	✅ 100.0%	9 / 9	0	100.0%
/src/PwrDrvr.LambdaDispatch.Router/Program.cs	❌ 0.0%	0 / 190	190	0.0%
/src/PwrDrvr.LambdaDisp..binLambdaInstanceQueue.cs	✅ 90.6%	29 / 32	3	91.7%
/src/PwrDrvr.LambdaDisp..inLambdaInstanceQueue2.cs	✅ 95.3%	61 / 64	3	100.0%
/src/PwrDrvr.LambdaDisp...Router/ShutdownSignal.cs	❌ 0.0%	0 / 1	1	-
/src/PwrDrvr.LambdaDispatch.Router/Startup.cs	❌ 0.0%	0 / 51	51	0.0%
/src/PwrDrvr.LambdaDispatch.Router/TokenBucket.cs	🟡 66.7%	12 / 18	6	100.0%
/src/PwrDrvr.LambdaDisp...Router/LambdaInstance.cs	✅ 100.0%	3 / 3	0	-
/src/PwrDrvr.LambdaDisp..Router/WeightedAverage.cs	✅ 91.7%	44 / 48	4	100.0%
/src/PwrDrvr.LambdaDisp..Router/TrailingAverage.cs	✅ 100.0%	36 / 36	0	100.0%
Overall	❌ 43.5%	2054 / 4718	2664	44.4%