string default: undefined when not null is false

[kostasb]

Describe the bug version: @xata.io/cli/0.11.5 string default: undefined shows next to string columns even when not null is false.

To reproduce, create a string column that doesn't have the not null constraint.

The undefined error shows both in the plan:

As well as after the migration is executed:

[alexfrancoeur]

Another one for @richardgill while he's in the CLI. Option for the bug squashing jamboree?