Fixed various CDS warnings (#242)

Author: beckermarc

app/common.cds

@@ -2,6 +2,7 @@
   Common Annotations shared by all apps
 */
 using {my.bookshop as my} from '../db/index';
+using {sap.common as common} from '@sap/cds/common';
 
 
 ////////////////////////////////////////////////////////////////////////////
@@ -158,8 +159,6 @@ annotate my.Reviews with {
         Text : book.title,
         TextArrangement : #TextOnly
     };
-    date
-    @title : '{i18n>Date}';
     rating
     @title : '{i18n>Rating}';
     text
@@ -382,26 +381,10 @@ annotate common.Currencies with
         {Value : descr}
     ]},
     FieldGroup #Extended : {Data : [
-        {Value : numcode},
-        {Value : minor},
-        {Value : exponent}
+        {Value : minorUnit}
     ]},
 });
 
-
-////////////////////////////////////////////////////////////////////////////
-//
-//	Currencies Elements
-//
-annotate common.Currencies with {
-    numcode
-    @title : '{i18n>NumCode}';
-    minor
-    @title : '{i18n>MinorUnit}';
-    exponent
-    @title : '{i18n>Exponent}';
-}
-
 ////////////////////////////////////////////////////////////////////////////
 //
 //	Fiori requires generated IDs to be annotated with @Core.Computed

db/reviews.cds

@@ -17,7 +17,6 @@ entity Reviews : cuid, managed {
 
 // input validation
 annotate Reviews with {
-    subject @mandatory;
     title @mandatory;
     rating @assert.range;
     book @mandatory @assert.target;

srv/admin-service.cds

@@ -3,7 +3,7 @@ using {my.bookshop as my} from '../db/index';
 
 @path : 'admin'
 service AdminService @(requires : 'admin') {
-  entity Books   as projection on my.Books actions {
+  entity Books   as projection on my.Books excluding { reviews } actions {
     action addToOrder(order_ID : UUID, quantity : Integer) returns Orders;
   }