[circle-eval-diff] Support random and directory input

[mhs4670go]

What

Let's support random and directory input.

Why

As of now, circle-eval-diff supports only hdf5 input data format. But sometimes, user want to run it without data set. And, directory input is needed as well.

[seanshpark]

But sometimes, user want to run it without data set.

Q) how is the test done without data set?

[mhs4670go]

@seanshpark Well, I thought test can be done because it is about comparing outputs of two model - output diff. But, after offline meeting with @jinevening, random input seems not to be needed because it is a bit useless because the random data has absolutely nothing to do with the data needed for quantization.