auth: Moved token and user to models package, added graphql endpoint to check token

graph2/schema/types/Token.gql

@@ -0,0 +1,8 @@
+# Token represents the data parsed and validated from the bearer token.
+type Token {
+  # The user represented in the token.
+  user: User!
+
+  # The permissions for the token.
+  permissions: [String!]!
+}

graph2/schema/types/User.gql

@@ -0,0 +1,8 @@
+# A user represents a member on the RPData platform.
+type User {
+  # The user's unique ID / username
+  id: String!
+
+  # What the user is permitted to do.
+  permissions: [String!]!
+}