Make generate-fix also generate go.mod files

[abheyshah]

When making custom fields I've used the replace directive in my apps go.mod file to point at my local versions of enum modules etc. This seems to work but I need to add go.mod files in my generated enum, tag and field modules. Maybe the generate-fix tool should be triggering a go mod init?

[Michael Ackley]

Yes, this is at the top of my to-do list currently