refactor(GraphQL): Rename objectId to id (#5985)

* refactor(GraphQL): Rename objectId to id

Renames `objectId` to `id` for the GraphQL API. Queries, mutations,
custom and generic types were updated.
Removes `RELATION_INPUT` and `POINTER_INPUT`. Now the user just need
to provide the ID of the object to link.

* fix: Column "id" not found on Postgres

* fix: Avoid deleting Parse class objectId

* fix: Undo objectId removal on mutations

* fix: Handle generic mutation id

src/GraphQL/transformers/mutation.js

@@ -119,7 +119,7 @@ const transformers = {
       value.add = value.add.map(input => ({
         __type: 'Pointer',
         className: targetClass,
-        objectId: input.objectId,
+        objectId: input,
       }));
       op.ops.push({
         __op: 'AddRelation',
@@ -133,7 +133,7 @@ const transformers = {
         objects: value.remove.map(input => ({
           __type: 'Pointer',
           className: targetClass,
-          objectId: input.objectId,
+          objectId: input,
         })),
       });
     }
@@ -171,11 +171,11 @@ const transformers = {
         objectId: nestedObjectToAdd.objectId,
       };
     }
-    if (value.link && value.link.objectId) {
+    if (value.link) {
       return {
         __type: 'Pointer',
         className: targetClass,
-        objectId: value.link.objectId,
+        objectId: value.link,
       };
     }
   },