## Problem
Currently, even if `LAMBDA_REMOTE_DOCKER=1`, we unzip the zip files in the directory they are in, which is usually /var/lib/localstack, which usually has a bind mount to the host.
On docker desktop, due to the use of grpc-FUSE (on macos), this can be very slow, about 200 times slower than on volumes / directly on the host. With experimental virtio filesystem enabled (also on macos), this can be reduced to about 30 times as slow, but still problematic.
This means a lambda may take a lot of time processing, for each additional layer some more. This especially affects nodejs lambdas with huge node_modules folders.

## Probable solution
At least if `LAMBDA_REMOTE_DOCKER=1`, we should leave the initial zip files on the bind mount (for persistence etc), but the working directories after unzipping should be located on non-bind mounts, to speed up the IO for unzipping.
@app.route("/2019-09-25/functions/<function>/event-invoke-config", methods=["DELETE"])
def delete_function_event_invoke_config(function):
    region = LambdaRegion.get()
    try:
        function_arn = func_arn(function)
        if function_arn not in region.lambdas:
            msg = f"Function not found: {function_arn}"
            return not_found_error(msg)
        lambda_obj = region.lambdas[function_arn]
    except Exception as e:
        return error_response(str(e), 400)
    lambda_obj.clear_function_event_invoke_config()
    return Response("", status=204)
@app.route("/2020-06-30/functions/<function>/code-signing-config", methods=["GET"])
def get_function_code_signing_config(function):
    region = LambdaRegion.get()
    function_arn = func_arn(function)
    if function_arn not in region.lambdas:
        msg = "Function not found: %s" % (function_arn)
        return not_found_error(msg)
    lambda_obj = region.lambdas[function_arn]
    if not lambda_obj.code_signing_config_arn:
        arn = None
        function = None
    else:
        arn = lambda_obj.code_signing_config_arn
    result = {"CodeSigningConfigArn": arn, "FunctionName": function}
    return Response(json.dumps(result), status=200)
@app.route("/2020-06-30/functions/<function>/code-signing-config", methods=["PUT"])
def put_function_code_signing_config(function):