Creating 2 datasets where the distribution has identical JSON causes them to share the same distribution

[grugnog]

Describe the bug

Having this happen is confusing to end users as if they later directly edit the shared distribution it will affect both datasets. This is also a rich source of potential edge cases and other bugs.

Steps To Reproduce

• Create dataset A
• Create dataset B with a distribution title/format/URL that is identical to dataset A
• Observe that only 1 distribution is created and that this distribution is referenced by both dataset A and B

Expected behavior

Each dataset should have distinct distributions.

Notes

This may be caused by the distribution JSON being used as a seed for the distribution UUID generation, in which case this could be resolved simply by switching to regular time based UUIDs.