Take in and display streaming search responses

We've talked for a long time about streaming data (ndjson or arrow record batches) from a STAC API. Once implemented in an API, **stac-map** would be a good demonstration case for consuming and displaying these streaming responses.

This depends on actually building a streaming response from a STAC API.

cc @bitner

The issue provides no files, tests, or entry points to start from. First confirm that the STAC API can produce streaming ndjson or Arrow record batches, then inspect how stac-map currently performs and displays search results. Done means stac-map consumes and displays the streaming search responses once the API support exists.

Written by the indexing model from the issue text.