Better progress reporting in get_buildings

[cholmes]

Right now if you do a get_buildings call on a big area it can take a long time, but you have no idea if it's working away or something has gone wrong. It'd be much better if it could report on how things are going. The ideal would be to report on what it's scanned remotely (maybe just in --verbose), and then to show some streaming progress as it downloads buildings.

This may not be possible, since it's DuckDB doing all the querying, but perhaps there's a way to hook into what it's doing and report out.

[cholmes]

Perhaps we could get the DuckDB location and at the very least figure out the total file size every 10 seconds to show that something is happening? And even better would be if we could make another connection to that duckdb instance and count the number of rows, and report out how many buildings have been downloaded.