chore: add llamaindex chat agent sample #591

Job	Run time
detect-changed-packages	5s
discover-testcases	3s
uipath-llamaindex/quickstart-agent / alpha	47s
uipath-llamaindex/quickstart-agent / staging	47s
uipath-llamaindex/simple-hitl-agent / cloud	43s
uipath-llamaindex/chat-models / cloud	3m 29s
uipath-llamaindex/simple-hitl-agent / staging	48s
uipath-llamaindex/chat-models / alpha	3m 23s
uipath-llamaindex/chat-models / staging	3m 37s
uipath-llamaindex/simple-hitl-agent / alpha	44s
uipath-llamaindex/quickstart-agent / cloud	49s
	15m 15s

Provide feedback