DuckDB-WASM: Add support for blob URLs for file loading

[maxzhuo]

I'm requesting support for blob URLs in DuckDB-WASM. Currently, using blob URLs with methods like LOAD and read_parquet() results in errors like:

// Attempt 1
conn.query(`LOAD 'blob:https://example.com/02b25a89-c64a-4463-9aef-010f0e5a9d84'`);

// Attempt 2
conn.query(`SELECT * FROM read_parquet('blob:https://example.com/55b05b9f-0e5a-4afb-ba15-7bb5801a7c7b')`);

Common Use Cases:
These patterns are common when working with browser-generated blobs:

1.Direct Blob Creation:

const blob = new Blob([Data]);
const blobURL = URL.createObjectURL(blob);

2.Extension Loading:

fetch('./parquet.duckdb_extension.wasm')
  .then(res => res.blob())
  .then(blob => {
    const blobURL = URL.createObjectURL(blob);
    conn.query(`LOAD '${blobURL}'`); // Currently fails
  });

3.Parquet File Loading:

fetch('./data.parquet')
  .then(res => res.blob())
  .then(blob => {
    const blobURL = URL.createObjectURL(blob);
    conn.query(`CREATE TABLE test AS SELECT * FROM read_parquet('${blobURL}')`); // Currently fails
  });