feat: simplify input and output types (typed-graphql-builder#49)

Simplifies input and output types of the resulting `TypedDocumentNode`

Prior art:
https://github.com/koskimas/kysely/blob/a8e28d9edd6284d5410f93bc24d3c6252add6ea1/src/util/type-utils.ts#L141


Before


![image](https://user-images.githubusercontent.com/502412/223389027-ad90a56f-e9e1-41c1-887f-e33950f09a9a.png)


After


![image](https://user-images.githubusercontent.com/502412/223388829-1443569a-c9fb-48ba-b632-b09b95eaf067.png)

Author: spion

src/postamble.ts

@@ -8,7 +8,7 @@ export function ${op}<Sel extends Selection<$RootTypes.${op}>>(
 ): TypedDocumentNode<GetOutput<Sel>, GetVariables<Sel>>
 export function ${op}<Sel extends Selection<$RootTypes.${op}>>(
   selectFn: (q: $RootTypes.${op}) => [...Sel]
-): TypedDocumentNode<GetOutput<Sel>, GetVariables<Sel>>
+): TypedDocumentNode<GetOutput<Sel>, Simplify<GetVariables<Sel>>>
 export function ${op}<Sel extends Selection<$RootTypes.query>>(name: any, selectFn?: any) {
   if (!selectFn) {
     selectFn = name

src/preamble.src.ts

@@ -144,16 +144,22 @@ type Selection<_any> = ReadonlyArray<$Field<any, any, any> | $UnionSelection<any
 
 type NeverNever<T> = [T] extends [never] ? {} : T
 
-export type GetOutput<X extends Selection<any>> = UnionToIntersection<
-  {
-    [I in keyof X]: X[I] extends $Field<infer Name, infer Type, any> ? { [K in Name]: Type } : never
-  }[keyof X & number]
-> &
-  NeverNever<
+type Simplify<T> = { [K in keyof T]: T[K] } & {}
+
+export type GetOutput<X extends Selection<any>> = Simplify<
+  UnionToIntersection<
     {
-      [I in keyof X]: X[I] extends $UnionSelection<infer Type, any> ? Type : never
+      [I in keyof X]: X[I] extends $Field<infer Name, infer Type, any>
+        ? { [K in Name]: Type }
+        : never
     }[keyof X & number]
-  >
+  > &
+    NeverNever<
+      {
+        [I in keyof X]: X[I] extends $UnionSelection<infer Type, any> ? Type : never
+      }[keyof X & number]
+    >
+>
 
 type PossiblyOptionalVar<VName extends string, VType> = undefined extends VType
   ? { [key in VName]?: VType }
@@ -247,7 +253,7 @@ function fieldToQuery(prefix: string, field: $Field<any, any, any>) {
               if (!argTypeForKey) {
                 throw new Error(`Argument type for ${key} not found`)
               }
-              const cleanType = argTypeForKey.replace('[', '').replace(']', '').replace('!', '')
+              const cleanType = argTypeForKey.replace('[', '').replace(']', '').replace(/!/g, '')
               return (
                 key +
                 ':' +