LYN-2726 Updated the Settings Registry Merge Utils logic to determine

the project root and engine root to fix issues with running the Editor
or AssetProcessor from within the project folder overriding the
project_path with the engine root bootstrap.cfg project_path entry

The order in which the project path is overridden as follows
1. The <engine-root>/bootstrap.cfg is first merged into the Settings
   Registry. Any '/Amazon/AzCore/Bootstrap/project_path' would be used
   if the following steps don't override that key.
2. Followed by general *.setreg/*.setregpatch files being merged into
   the Settings Registry which can override the
   '/Amazon/AzCore/Bootstrap/project_path' key
3. Next a project.json file searched upwards from the current executable
   directory to determine the project path
4. Finally if a command line parameter that overrides the project path
   is supplied it is used instead

Code/Framework/AzToolsFramework/AzToolsFramework/Application/ToolsApplication.h

@@ -150,8 +150,6 @@ namespace AzToolsFramework
         void EnterEditorIsolationMode() override;
         void ExitEditorIsolationMode() override;
         bool IsEditorInIsolationMode() override;
-        const char* GetEngineRootPath() const override;
-        const char* GetEngineVersion() const override;
 
         void CreateAndAddEntityFromComponentTags(const AZStd::vector<AZ::Crc32>& requiredTags, const char* entityName) override;
 
@@ -174,7 +172,6 @@ namespace AzToolsFramework
 
         void CreateUndosForDirtyEntities();
         void ConsistencyCheckUndoCache();
-        void InitializeEngineConfig();
         AZ::Aabb                            m_selectionBounds;
         EntityIdList                        m_selectedEntities;
         EntityIdList                        m_highlightedEntities;
@@ -186,9 +183,6 @@ namespace AzToolsFramework
         bool                                m_isInIsolationMode;
         EntityIdSet                         m_isolatedEntityIdSet;
 
-        class EngineConfigImpl;
-        AZStd::unique_ptr<EngineConfigImpl> m_engineConfigImpl;
-
         EditorEntityAPI* m_editorEntityAPI = nullptr;
 
         EditorEntityManager m_editorEntityManager;