Update scope declaration invariant to support error grouping

This invariant interpolated values into the `reason` which prevent our internal 
tooling from grouping related errors. This PR updates to make the reason static 
and interpolate the description.

compiler/packages/babel-plugin-react-forget/src/ReactiveScopes/CodegenReactiveFunction.ts

@@ -435,8 +435,8 @@ function codegenReactiveScope(
   );
   if (testCondition === null) {
     CompilerError.invariant(firstOutputIndex !== null, {
-      reason: `Expected scope '@${scope.id}' to have at least one declaration`,
-      description: null,
+      reason: `Expected scope to have at least one declaration`,
+      description: `Scope '@{scope.id} has no declarations`,
       loc: null,
       suggestions: null,
     });