Adding DuckDB as a SQL Database for the to_sql() function

[pdet]

This PR adds DuckDB as a direct possibility to the to_sql() function.
It basically uses DuckDBs internal pandas integration to load data frames as a duckdb table.

I think I've added duckdb correctly as an optional dependency, I'm happy to fix it if I made any mistake :-)

I'm also really supporting the optional if_exists attribute, if any other attribute is a 'must-have' I'm also happy to do so.

[alimcmaster1]

Hey, thanks for the PR, DuckDb looks interesting. Might be worth opening an issue + getting agreement from core team that this is something we want to support before continuing dev here

[mroeschke]

I commented on your created issue as well, but noted in #45678 (comment) that it would be great to have a SQL engine interface to implement Duck DB instead of having Duck DB specific code here

[jreback]

agree with @mroeschke recommendations here.

[mroeschke]

Thanks for the pull request, but as mentioned, in #45678 (comment), pandas would need to support a DB engine interface first before supporting DuckDB directly. Closing for now, but happy to have progress on the interface!