Spring Cleaning → removing obsolete stuff, and moved non-app things to ./etc (#810)

* Remove obsolete stuff, and moved non-app things to ./etc
* remove test
* Update package-lock

---------

Co-authored-by: Christian Georgi <christian.georgi@sap.com>

etc/data-viewer/srv/data-service.cds

@@ -0,0 +1,30 @@
+/**
+ * Exposes data + entity metadata
+ */
+@requires:'authenticated-user'
+@odata service DataService @( path:'-data' ) {
+
+  /**
+   * Metadata like name and columns/elements
+   */
+  entity Entities @cds.persistence.skip {
+    key name : String;
+    columns: Composition of many {
+      name :  String;
+      type :  String;
+      isKey:  Boolean;
+    }
+  }
+
+  /**
+   * The actual data, organized by column name
+   */
+  entity Data @cds.persistence.skip {
+    key ID   : String;   // to be OData-compliant
+    record   : array of {
+      column : String;
+      data   : String;
+    }
+  }
+
+}