anvil.server.call inside web workers

[s-cork]

We currently can't use anvil.server.call from inside a web worker, (it doesn't exist)

but if we can fix #100 Then we can create a poor man's anvil.server.call implementation, which will look something like

from anvil.js.window import fetch

def call(fn_name, *args, **kws):
    rv = fetch(get_api_origin() + f"/anvil_labs_private_call?name={fn_name}", {
        "method": "POST",
        "body": serialize(args, kws)
    })
    if rv.error:
        raise reconstruct(rv.error)
    else:
        return rv.result

# in anvil_labs server modul
@anvil.server.http_endpoint("/anvil_labs_private_call")
def anvil_labs_private_call(name):
    args, kws = deserialize(anvil.server.request.body)
    rv = {"result": None, "error": None}
    try:
        rv["result"] = anvil.server.call(name, *args, **kws)
    except Exceptions as e:
        rv["error"] = serialize_error(e)

    return rv        

We'd have to be careful about cors stuff, but it might be alright since the app origin would be the same Serialization might be a pain.

If we want to really go for it we could adapt kompot for the purpose! And then maybe everything would just... work?