feat: add getExecution query

packages/backend/src/graphql/queries/get-execution.ts

@@ -0,0 +1,24 @@
+import Context from '../../types/express/context';
+
+type Params = {
+  executionId: string;
+};
+
+const getExecution = async (
+  _parent: unknown,
+  params: Params,
+  context: Context
+) => {
+  const execution = await context.currentUser
+    .$relatedQuery('executions')
+    .withGraphFetched({
+      flow: {
+        steps: true
+      }
+    })
+    .findById(params.executionId);
+
+  return execution;
+};
+
+export default getExecution;