Redo everything with Schema Stitching

So...I potentially implemented some abstractions in here that were not necessary to do on my own. Schema stitching will take multiple schemas and merge them into one. So I don't need to go and traverse and combine the ASTs myself. Try out the graphql-tools makeExecutableSchema and mergeSchemas functions. I did this in prendus-app with Prisma, and it's working very well