Add support for funky column names with polars lazy=True

[J-Meyers]

Fixes: duckdb/duckdb#18875

[dsevilla]

Looks good to me taking into account the usage of double quotes for names in DuckDB.

[soren-petersen]

@J-Meyers : Thanks for helping fix this! ❤️

[soren-petersen]

I may be wrong, but is seems the patch will not work if the column name contains a double quote.

I suspect changing the following line:

cols = ",".join(f'"{col}"' for col in with_columns)

to

cols = ",".join(f'"{col.replace('\"', '\"\"')}"' for col in with_columns)

would fix this.

[J-Meyers]

I may be wrong, but is seems the patch will not work if the column name contains a double quote.

I suspect changing the following line:

cols = ",".join(f'"{col}"' for col in with_columns)

to

cols = ",".join(f'"{col.replace('\"', '\"\"')}"' for col in with_columns)

would fix this.

@soren-petersen
Good catch, I added a test and fixed the handling of those: d1b01d8
Switched to an explicit function because python was complaining about backslashes within fstrings

[evertlammerts]

Looks good, thanks for the fix! FYI I switched the base to main and back to trigger the PR workflow, which had a bug. If the tests succeed I'll merge tomorrow and this will go into 1.4.0 (planned for Wed).