Fix Manage Books UI (#475)

Use author_ID, as this brings proper text representation and also holds
Value Helps.
Fixes #474

Author: beckermarc

app/admin/fiori-service.cds

@@ -45,8 +45,6 @@ annotate AdminService.Books with @(UI : {
         }
     ],
     FieldGroup #General : {Data : [
-        {Value : title},
-        {Value : author_ID},
         {Value : genre_ID},
         {Value : descr},
     ]},

app/browse/fiori-service.cds

@@ -13,7 +13,7 @@ annotate CatalogService.Books with @(UI : {
         TypeName : '{i18n>Book}',
         TypeNamePlural : '{i18n>Books}',
         Title : {Value : title},
-        Description : {Value : author.name}
+        Description : {Value : author_ID}
     },
     Identification : [
         {Value : title},

app/common.cds

@@ -23,10 +23,7 @@ annotate my.Books with
         LineItem : [
             {Value : ID},
             {Value : title},
-            {
-                Value : author.name,
-                Label : '{i18n>Author}'
-            },
+            {Value : author_ID},
             {Value : genre.name},
             {Value : stock},
             {Value : price},
@@ -57,7 +54,7 @@ annotate my.Books with
     TypeNamePlural : '{i18n>Books}',
     TypeImageUrl : 'sap-icon://course-book',
     Title : {Value : title},
-    Description : {Value : author.name}
+    Description : {Value : author_ID}
 }, });