Add the ability to generate random UUIDs for UUID cells

[rrvsh]

I propose adding functionality to the insert/update row contextual menu to allow generating random UUIDs for column values with the UUID type. This UI pattern is already present with e.g. timestampz:

We could add a edit icon in the same style conditional on the type of column being uuid and allow generating a random UUID to fill in the field. Happy to implement this myself if you guys approve of this request, btw :)

[k1ng-arthur]

when you specify a column type you can specify random UUID and then it comes up as a default when you enter a row so you don't have to add anything. How would what you propose differ?