Bug: Send abort signal to http_stream on drop/close

[insipx]

test_dm_stream_all_messages only works if each stream call is in a separate scope. This probably isn't a blocker overall for streaming but should be fixed in a followup by sending the abort signal to the web stream in the http api

Abort code in wasm reqwest: https://github.com/seanmonstar/reqwest/blob/b65a03c698e9e11cadb11d9815c1cdd5f556738e/src/wasm/client.rs#L225

otherwise streams in browser may hang