sdk: implement startAgentRun #3993

Job	Run time
build-and-check	2m 32s
test-cli	34s
test-backend	1m 19s
test-.agents	34s
test-integration-cli	30s
test-npm-app	34s
test-packages/agent-runtime	47s
test-common	36s
test-integration-web	37s
test-integration-.agents	36s
test-integration-common	34s
test-web	34s
test-integration-npm-app	38s
test-integration-backend	33s
test-integration-packages/agent-runtime	31s
	11m 29s

Provide feedback