Expose DistributedSampler RNG seed argument

[janEbert]

This way, it becomes easier to randomly vary the order of the data.

What does this PR do?

Exposes the DistributedSampler's seed argument in the get_sampler utility function. Since the default value is already seed=0, #3723.

What issue(s) does this change relate to?

Fixes #3723

Before submitting

• Have you read the contributor guidelines?
• Is this change a documentation change or typo fix? If so, skip the rest of this checklist.
• Was this change discussed/approved in a GitHub issue first? It is much more likely to be merged if so.
• Did you update any related docs and document your change?
• Did you update any related tests and add any new tests related to your change? (see testing)
• Did you run the tests locally to make sure they pass?
• Did you run pre-commit on your change? (see the pre-commit section of prerequisites)

@mvpatel2000

[dakinggg]

Thanks!