The `open_history_client()` provider endpoint can *optionally*
deliver a `frame_types: dict[int, pendulum.Duration]` subsection in its
`config: dict[str, dict]` (as was implemented with the `ib` backend).
This allows the `tsp` backfilling machinery to use this "recommended
frame duration" to subtract from the `last_start_dt` any time a `NoData`
gap is signalled by the `get_hist()` call allowing gaps to be ignored
safely without missing history by knowing the next earliest dt we can
query from using the `end_dt`. However, currently all crypto$ providers
haven't implemented this feat yet..
As such only try to use the `frame_types` feature if provided when
handling `NoData` conditions inside `tsp.start_backfill()` and otherwise
raise as normal.
Nelson Torres
f31094f0d7