Re-enabled secured hierarchical-data test

test/hierarchical-data.test.js

@@ -1,6 +1,6 @@
 const {expect} = require('./capire')
-// global.cds = undefined
 const cds = require ('@sap/cds')
+const cwd = process.cwd(); process.chdir (__dirname) //> only for internal CI/CD@SAP
 
 const model = cds.parse(`
   entity Categories {
@@ -21,6 +21,8 @@ describe('Hierarchical Data', ()=>{
     expect (cds.db.model) .to.exist
 	})
 
+	after(()=> process.chdir(cwd))
+
 	it ('supports deeply nested inserts', ()=> INSERT.into (Cats,
     { ID:100, name:'Some Cats...', children:[
       { ID:101, name:'Cat', children:[