Should history manager cache results? #15388

JupyterLab has inline completion which searches the history based on what user types. Since user usually types extra characters, it could be faster if instead of redoing the computation we filtered within previous results. In ipykernel this is exposed in https://github.com/ipython/ipykernel/blob/213cbf668219fe4e62afc97ee875bb9ead893899/ipykernel/ipkernel.py#L626-L641

Same optimization might be useful for IPython history completions too.