WASM support

[atheriel]

Describe the bug

read_stat does not appear to work on DuckDB WASM. Testing on https://shell.duckdb.org/ I see:

duckdb> INSTALL read_stat FROM community;
duckdb> LOAD read_stat;
IO Error: Extension 'read_stat' did not contain the expected entrypoint function 'read_stat_init'

Check whether the bug is not upstream

[N/A] I have tried and have not been able to reproduce the issue with with pyreadstat, haven, or another library based on ReadStat and understand my issue will be immediately closed as invalid if not.

Check whether a file is available to reproduce the issue with

[N/A] I will attach a file to reproduce the issue with produced by SAS, SPSS, or Stata which I am willing to share and understand my issue will not be investigated without such a file.

DuckDB platform (please complete the following information):

[ ] Windows
[ ] macOS
[ ] Linux
[x] WebAssembly (WASM)
[ ] Multiple