Federation branch - Modified templates to check for updateMany; added federation prefix from paljs/generator; updated paljs/generator package

[johnkm516]

As per title.

Paljs/generator's generator.run() now returns the entire dmmf document. You might find that useful for getting the model names, I also added a bunch of useful maps as type extensions. These include federation related fields for model fields, generateUpdateMany for models which return a boolean value whether or not a model should generate an updateMany mutation or not.

updateMany should not be generated if a model contains only unique fields or relations; there would be no valid arguments as in order for updateMany to work you would have to update a single value over multiple instances of the object which is impossible if all the fields are unique. Therefore Prisma itself will not generate any args for the updateMany, which caused a compile error in the original paljs/Generator. I have fixed this issue in my fork, and updated the templates in this pull request accordingly.

[johnkm516]

For reference, this resolves #10