eeschema: Prevent crash on move/drag re-entry

Restarting a move/drag operation breaks the stack by starting the tool
without popping it on exit.

TODO: implement RAII for these stack push/pop

common/eda_base_frame.cpp

@@ -161,6 +161,7 @@ EDA_BASE_FRAME::~EDA_BASE_FRAME()
 }
 
 
+// TODO: Implement an RAII mechanism for the stack PushTool/PopTool pairs
 void EDA_BASE_FRAME::PushTool( const std::string& actionName )
 {
     m_toolStack.push_back( actionName );

eeschema/tools/sch_move_tool.cpp

@@ -119,9 +119,6 @@ int SCH_MOVE_TOOL::Main( const TOOL_EVENT& aEvent )
     else
         return 0;
 
-    std::string tool = aEvent.GetCommandStr().get();
-    m_frame->PushTool( tool );
-
     if( m_moveInProgress )
     {
         auto sel = m_selectionTool->GetSelection().Front();
@@ -160,6 +157,8 @@ int SCH_MOVE_TOOL::Main( const TOOL_EVENT& aEvent )
     TOOL_EVENT* evt = const_cast<TOOL_EVENT*>( &aEvent );
     VECTOR2I    prevPos;
 
+    std::string tool = aEvent.GetCommandStr().get();
+    m_frame->PushTool( tool );
     m_cursor = controls->GetCursorPosition();
 
     // Main loop: keep receiving events