message: Fix go to definition when a local schema file is provided
diff: // FileSchemaProvider (FileProvider (SDL || IntrospectionResult) => schema)
  import { GraphQLSchema, buildClientSchema, Source, buildSchema } from "graphql";
  import { readFileSync } from "fs";
  -import { extname } from "path";
  +import { extname, resolve } from "path";
  import { GraphQLSchemaProvider, SchemaChangeUnsubscribeHandler } from "./base";
  import { NotificationHandler } from "vscode-languageserver";
  @@ -39,7 +39,8 @@ export class FileSchemaProvider implements GraphQLSchemaProvider {
  this.schema = buildClientSchema({ __schema });
  } else if (ext === ".graphql" || ext === ".graphqls" || ext === ".gql") {
  - this.schema = buildSchema(new Source(result, path));
  + const uri = `file://${resolve(path)}`;
  + this.schema = buildSchema(new Source(result, uri));
  }
  if (!this.schema) throw new Error(`Schema could not be loaded for ${path}`);
  return this.schema;
  