graphql: fix global ids in upgraded types

closes RECNVS-505

Test plan:
  querying for the id of any object should return an opaque identifier
  (it should different from that object's _id)

Change-Id: I738fa631915135df03e7e381f0a41d92a7813e06
Reviewed-on: https://gerrit.instructure.com/155688
Tested-by: Jenkins
Reviewed-by: Jonathan Featherstone <jfeatherstone@instructure.com>
QA-Review: Jonathan Featherstone <jfeatherstone@instructure.com>
Product-Review: Cameron Matheson <cameron@instructure.com>

app/graphql/types/assignment_type.rb

@@ -65,6 +65,7 @@ module Types
       Assignment::ALLOWED_GRADING_TYPES.each { |type| value(type) }
     end
 
+    global_id_field :id
     field :_id, ID, "legacy canvas id", null: false, method: :id
 
     field :name, String, null: true

app/graphql/types/discussion_type.rb

@@ -23,9 +23,7 @@ module Types
     implements GraphQL::Relay::Node.interface
     implements Interfaces::TimestampInterface
 
-    ## TODO: something like this
-    #implements Interfaces::LegacyNode
-
+    global_id_field :id
     field :_id, ID, "legacy canvas id", null: false, method: :id
   end
 end

app/graphql/types/quiz_type.rb

@@ -24,6 +24,7 @@ module Types
     implements GraphQL::Relay::Node.interface
     implements Interfaces::TimestampInterface
 
+    global_id_field :id
     field :_id, ID, "legacy canvas id", method: :id, null: false
   end
 end

app/graphql/types/submission_type.rb

@@ -26,6 +26,7 @@ module Types
     alias :submission :object
 
     # not doing a legacy canvas id since they aren't used in the rest api
+    global_id_field :id
 
     field :assignment, AssignmentType, null: true
     def assignment

app/graphql/types/user_type.rb

@@ -30,6 +30,7 @@ module Types
     implements GraphQL::Relay::Node.interface
     implements Interfaces::TimestampInterface
 
+    global_id_field :id
     field :_id, ID, "legacy canvas id", null: false, method: :id
 
     field :name, String, null: true

schema.graphql

@@ -29,8 +29,6 @@ type Assignment implements Node & Timestamped {
   dueAt: DateTime
   gradingType: GradingType
   htmlUrl: URL
-
-  # ID of the object.
   id: ID!
   lockAt: DateTime
   lockInfo: LockInfo
@@ -366,8 +364,6 @@ type Discussion implements Node & Timestamped {
   # legacy canvas id
   _id: ID!
   createdAt: DateTime
-
-  # ID of the object.
   id: ID!
   updatedAt: DateTime
 }
@@ -643,8 +639,6 @@ type Quiz implements Node & Timestamped {
   # legacy canvas id
   _id: ID!
   createdAt: DateTime
-
-  # ID of the object.
   id: ID!
   updatedAt: DateTime
 }
@@ -701,8 +695,6 @@ type Submission implements Node & Timestamped {
   grade: String
   gradedAt: DateTime
   gradingStatus: String
-
-  # ID of the object.
   id: ID!
   score: Float
   state: SubmissionState!
@@ -794,8 +786,6 @@ type User implements Node & Timestamped {
     # only return enrollments for this course
     courseId: ID
   ): [Enrollment!]!
-
-  # ID of the object.
   id: ID!
   name: String