Remove Context Menu in Empty Space of Hierarchy Navigator

Previously, a single RMB-click at empty space had no effect, while a
double-click opened the context menu. As per the @sethhillbrand suggestion,
instead of fixing this, no context menus should appear in empty space, as
it is not necessary. To address this, the wxEVT_RIGHT_UP event binding has
been removed by unbinding it from both the constructor and destructor.
Additionally, the onRightClick(wxMouseEvent& aEvent) method has been
removed, as it is linked to wxEVT_RIGHT_UP and is no longer necessary.

Fixes #17962

eeschema/widgets/hierarchy_pane.cpp

@@ -108,7 +108,6 @@ HIERARCHY_PANE::HIERARCHY_PANE( SCH_EDIT_FRAME* aParent ) :
     Bind( wxEVT_TREE_ITEM_RIGHT_CLICK, &HIERARCHY_PANE::onTreeItemRightClick, this );
     Bind( wxEVT_CHAR_HOOK, &HIERARCHY_PANE::onCharHook, this );
     m_tree->Bind( wxEVT_TREE_END_LABEL_EDIT, &HIERARCHY_PANE::onTreeEditFinished, this );
-    m_tree->Bind( wxEVT_RIGHT_UP, &HIERARCHY_PANE::onRightClick, this );
     m_events_bound = true;
 }
 
@@ -120,7 +119,6 @@ HIERARCHY_PANE::~HIERARCHY_PANE()
     Unbind( wxEVT_TREE_ITEM_RIGHT_CLICK, &HIERARCHY_PANE::onTreeItemRightClick, this );
     Unbind( wxEVT_CHAR_HOOK, &HIERARCHY_PANE::onCharHook, this );
     m_tree->Unbind( wxEVT_TREE_END_LABEL_EDIT, &HIERARCHY_PANE::onTreeEditFinished, this );
-    m_tree->Unbind( wxEVT_RIGHT_UP, &HIERARCHY_PANE::onRightClick, this );
 }
 
 
@@ -373,12 +371,6 @@ void HIERARCHY_PANE::onTreeItemRightClick( wxTreeEvent& aEvent )
 }
 
 
-void HIERARCHY_PANE::onRightClick( wxMouseEvent& aEvent )
-{
-    onRightClick( wxTreeItemId() );
-}
-
-
 void HIERARCHY_PANE::onRightClick( wxTreeItemId aItem )
 {
     wxMenu          ctxMenu;

eeschema/widgets/hierarchy_pane.h

@@ -116,7 +116,6 @@ private:
     void onSelectSheetPath( wxTreeEvent& aEvent );
 
     void onTreeItemRightClick( wxTreeEvent& aEvent );
-    void onRightClick( wxMouseEvent& aEvent );
     void onRightClick( wxTreeItemId aItem );
     void onCharHook( wxKeyEvent& aKeyStroke );
     void onTreeRightClick( wxTreeEvent& event );