ci: Add the scalars that doesn't exist in GraphQL, add type Query as …

…expected in introspection query (#554)

packages/subgraph/schema.graphql

@@ -1,3 +1,13 @@
+# This is just for generating introspection query purposes.
+" Byte array, represented as a hexadecimal string. Commonly used for Ethereum hashes and addresses. "
+scalar Bytes
+" Large integers. Used for Ethereum's `uint32`, `int64`, `uint64`, ..., `uint25`6 types. Note: Everything below `uint32`, such as `int32`, `uint24` or `int8` is represented as `i32`. "
+scalar BigInt
+" Query type, required to generate introspection query. "
+type Query @entity {
+  id: ID!
+}
+
 # Types
 
 # Token