Set a default uuid for the XForm uuid field

[DavisRayM]

Feature / Change Request

I think changing the default of the XForm uuid field to uuid.uuid4() from its current default would be a nice Idea.

It would also be nice if this change was implemented with #1773.

Benefits

• Merged Datasets will have a default uuid
• uuid is slowly becoming a must have field for the XForm model. Especially if Create consistent Enketo URLs #1775 is merged.

CC: @ukanga @ivermac @pld @WinnyTroy @lincmba

[pld]

Can you please describe why you think this would be worthwhile?

[DavisRayM]

Can you please describe why you think this would be worthwhile?

I think implementing this would remove the worry of the field being an empty string. Which affects a few features the FLOIP endpoint is one feature affected as it utilizes the uuid quite heavily.

This doesn't affect the XForm model in particular as the uuid is usually filled in when one creates the XForm through the viewset / serializer. Any other steps used to create the XForm instance leads to the field being empty unless explicitly passed in.

[pld]

OK cool, I'm not certain, but I'd think things would break with a null UUID, if that's true this is more of an error fix than a feature request. @DavisRayM can you add the Error or Enhancement label based on this.

This sounds worthwhile.