Test test_random_scenario is flaky

[G-D-Petrov]

Describe the bug

The test test_random_scenario is flaky as it relies on the on date time to create random enough snapshot names. If the snapshot names are not unique, arcticdb raises an exception and the test fails. The names should be made more unique to make sure that there is no collision.

See this run: https://github.com/man-group/ArcticDB/actions/runs/10474554461/job/29010220054?pr=1778

Steps/Code to Reproduce

See this CI run for repro: https://github.com/man-group/ArcticDB/actions/runs/10474554461/job/29010220054?pr=1778

Expected Results

The test should be stable and not throw false negatives.

OS, Python Version and ArcticDB Version

Python 3.7 Windows

Backend storage used

Memory

Additional Context

No response