Add support for remote files as well as local files

[ramonvermeulen]

• added support for remote files as well as local files, uses purely the filename to load into the buffer and not the full https/http url

E.g. otherwise you are writing a url instead of a file or file path to the virtual wasm file system which will cause errors. Docs do not need to be changed, you can just configure a url, e.g. https://storage.googleapis.com/some-bucket/some_file.duckdb or just a file path relative to the public folder, e.g. ./some_file.duckdb as config.path property.

solves issue https://github.com/holdenmatt/duckdb-wasm-kit/issues/5

[holdenmatt]

Thanks for the PR, LGTM!