[onert/test] Generate random input on each run

[hseok-oh]

What

Let's generate input random data per each run as default. And we can introduce additional argument to test driver to run with fixed input data on random input data generation. (ex. --fixed-input)

Why

Current test tools (onert_run, etc) fill input data once and reuse when it run multiple times. We need to support changing input data on each run to test more various input case. For debugging, we can introduce additional argument to support multiple run with fixed input data.