[Doc] Make naming groups consistent in App

The identifier for groups/topics such as "Document" that have a class
with the samen name are suffixed with "Group", so the identifier becomes
"DocumentGroup".  For groups/topics with no ambiguity the identifier
matches the topic name closely, for example "ExpressionFramework" for
topic "Expression Framework".

src/App/Expression.h

@@ -111,10 +111,10 @@ protected:
 
 /**
   * @brief %Base class for expressions.
-  * @ingroup Expression
+  * @ingroup ExpressionFramework
   *
   * @details For a high-level overview of the %Expression framework see topic
-  * @ref Expression "Expression Framework".
+  * @ref ExpressionFramework "Expression Framework".
   */
 class AppExport Expression : public Base::BaseClass {
     TYPESYSTEM_HEADER_WITH_OVERRIDE();

src/App/Property.h

@@ -46,7 +46,7 @@ class ObjectIdentifier;
 
 /**
  * @brief %Base class of all properties
- * @ingroup PropFrame
+ * @ingroup PropertyFramework
  *
  * @details This is the father of all properties. Properties are objects which that used
  * in the document tree to parameterize e.g. features and their graphical output.
@@ -56,7 +56,7 @@ class ObjectIdentifier;
  * possible properties.  It is also possible to define user properties
  * and use them in the framework.
  *
- * For a more high-level overview see topic @ref PropFrame "Property Framework".
+ * For a more high-level overview see topic @ref PropertyFramework "Property Framework".
  */
 class AppExport Property: public Base::Persistence
 {

src/App/core-app.dox

@@ -3,9 +3,9 @@
  * @ingroup CORE
  * @brief The part of FreeCAD that works without GUI (console or server mode)
  * @details It contains the App namespace and defines core concepts such as
- * @ref DocumentGroup "Document", @ref DocObject "Document Object", the @ref
- * Expression "Expression Framework", and the @ref PropFrame
- * "Property Framework".
+ * @ref DocumentGroup "Document", @ref DocumentObjectGroup "Document Object",
+ * the @ref ExpressionFramework "Expression Framework", and the @ref
+ * PropertyFramework "Property Framework".
  */
 
 /**
@@ -38,19 +38,19 @@
  */
 
 /**
- * @defgroup DocObject Document Object
+ * @defgroup DocumentObjectGroup Document Object
  * @ingroup APP
  * @brief %Base class of all objects handled in the Document.
  */
 
 /**
- * @defgroup Expression Expressions framework
+ * @defgroup ExpressionFramework Expressions framework
  * @ingroup APP
  * @brief The expression system allows users to write expressions and formulas that produce values
  */
 
 /**
- * @defgroup PropFrame Property framework
+ * @defgroup PropertyFramework Property framework
  * @ingroup APP
  * @brief System to access object properties.
  *