LX-216 Don't duplicate UUIDs

[rogup]

What? Why?

Closes https://github.com/DigitalCommons/land-explorer-front-end/issues/216

Making a snapshot / copy of a map creates objects with duplicate UUIDs. This causes unwanted behaviour e.g. if you change the description of a marker in the original map, its description changes in any snapshots too.

These changes fix this logic, so that the objects in the snapshot or copy have new UUIDs.

What should we test?

• Create a new map with a marker, polygon and line
• Create a copy of the map.
• Go to the original map and change the title/description of each object
• Check that these values haven't changed in the copy

Repeat the above for a snapshot

Release notes

Deployment notes

Documentation updates

[lin-d-hop]

had a pretty thorough play with this and everything is working perfectly :)