Support for spilling to OPFS

[debanjandhar12]

What happens?

Currently, setting

SET temp_directory='opfs://temp'

causes this error when memory overflow occurs:
Opening file 'opfs://temp/duckdb_temp_storage_S96K-0' failed with error: Error: No OPFS access handle registered with name: opfs://temp/duckdb_temp_storage_S96K-0

To Reproduce

N/a

Browser/Environment:

Chrome

Device:

Linux

DuckDB-Wasm Version:

1.29.1-dev260.0

DuckDB-Wasm Deployment:

N/a

Full Name:

Debanjan Dhar

Affiliation:

N/a