Showcase how to integrate DB-specific functions (#201)

Augment `AdminService.Author` by 2 fields `age` and `lifetime` whose
values are computed by SQLite and HANA-specific functions.

Don't do this in bookshop directly, to keep it simple.  Instead, use
the fiori module, which also allows to integrate the fields in the UI.

Co-authored-by: Daniel <daniel.hutzel@sap.com>

fiori/app/admin/fiori-service.cds

@@ -1,4 +1,4 @@
-using AdminService from '@capire/bookshop';
+using { AdminService } from '../../db';
 
 ////////////////////////////////////////////////////////////////////////////
 //
@@ -39,6 +39,27 @@ annotate AdminService.Books with @(
 	}
 );
 
+annotate AdminService.Authors with @(
+	UI: {
+		HeaderInfo: {
+			Description: {Value: lifetime}
+		},
+		Facets: [
+			{$Type: 'UI.ReferenceFacet', Label: '{i18n>Details}', Target: '@UI.FieldGroup#Details'},
+			{$Type: 'UI.ReferenceFacet', Label: '{i18n>Books}', Target: 'books/@UI.LineItem'},
+		],
+		FieldGroup#Details: {
+			Data: [
+				{Value: placeOfBirth},
+				{Value: placeOfDeath},
+				{Value: dateOfBirth},
+				{Value: dateOfDeath},
+				{Value: age, Label: '{i18n>Age}'},
+			]
+		},
+	}
+);
+
 
 
 ////////////////////////////////////////////////////////////