## 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.
---
    operationId: 'updateFunctionCode'
    parameters:
        - name: 'request'
          in: body
    """
    region = LambdaRegion.get()
    arn = func_arn(function)
    lambda_function = region.lambdas.get(arn)
    if not lambda_function:
        return not_found_error("Function not found: %s" % arn)
    data = json.loads(to_str(request.data))
    lambda_function.code = data
    result = set_function_code(lambda_function)
    if isinstance(result, Response):
        return result
    if data.get("Architectures"):
        lambda_function.architectures = data["Architectures"]
    lambda_function.last_modified = datetime.utcnow()
    result.update(format_func_details(lambda_function))
    if data.get("Publish"):
        result["Version"] = publish_new_function_version(arn)["Version"]
    return jsonify(result or {})
@app.route("%s/functions/<function>/code" % API_PATH_ROOT, methods=["GET"])
def get_function_code(function):
    """Get the code of an existing function
    ---
    operationId: 'getFunctionCode'
    parameters:
    """