* [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

some discrepancies between vivado and HLS here so sometimes AXI
lite signals appear as e.g. ifname_AREADY whereas other times it
is ifname_aready

no rtlsim implementation for impl_style=vivado right now