* [StreamingFC] introduce make_weight_file helper function

not yet wired into the rest of the class

* [Test] use make_weight_file helper in runtime weight test

* [Test] make runtime weight test work with different aspect ratio

* [Refactor] StreamingFC: use make_weight_file in generate_params

also fixed corresponding tests

several channels getting out the same value, causing different
topk outputs from npy and finn

called prior to transformations now by default