Share keys

[tephenavies]

What this PR does

Fixes #4774.

Ports shareKeys from version 7.

This PR is now a draft because I haven't updated CHANGES.md and I'm not sure whether to change how share data loading uses upsertModelFromJson while I'm here:

• It's kinda neat that restoring share data can both update or insert models depending on if they're user-added, or from catalog, but it gets it wrong and tries to insert half a model if the model has been removed from a newer catalog
• Restoring from share is quite a special thing, so we should maybe do the insert/update & shareKey logic outside of upsertModelFromJson

Apart from that, this functionality should work well in the following scenarios:

• JSON catalogs (requires implementing a shareKeys adder to catalog-converter)
• JSON catalog share link against a catalog imported into magda (requires implementing a shareKeys adder to init-to-magda)

Magda catalog share link where the item has moved is partially supported, but only if old share link ids manage to match against shareKeys in parts of the catalog already loaded when the share data is applied.

Checklist

• There are unit tests to verify my changes are correct or unit tests aren't applicable (if so, write quick reason why unit tests don't exist)
• I've updated CHANGES.md with what I changed.

[nf-s]

Revert #4979 after merging this. Related to this issue https://github.com/TerriaJS/qld-digital-twin/issues/237

After reverting close this issue - #4978

[nf-s]

Love it! thanks @steve9164
Just a few small things + Changes.md entry

[nf-s]

I was being too nitpicky - all good
Thanks crispy