Hopefully the last of the symbol id escaping issues.

Fixes https://gitlab.com/kicad/code/kicad/issues/8694

common/widgets/grid_text_button_helpers.cpp

@@ -209,7 +209,7 @@ protected:
         KIWAY_PLAYER* frame = m_dlg->Kiway().Player( FRAME_SCH_VIEWER_MODAL, true, m_dlg );
 
         if( frame->ShowModal( &symbolId, m_dlg ) )
-            SetValue( symbolId );
+            SetValue( UnescapeString( symbolId ) );
 
         frame->Destroy();
     }

eeschema/dialogs/dialog_edit_symbols_libid.cpp

@@ -509,6 +509,10 @@ void DIALOG_EDIT_SYMBOLS_LIBID::AddRowToGrid( bool aMarkRow, const wxString& aRe
 wxString getLibIdValue( const WX_GRID* aGrid, int aRow, int aCol )
 {
     wxString rawValue = aGrid->GetCellValue( aRow, aCol );
+
+    if( rawValue.IsEmpty() )
+        return rawValue;
+
     wxString itemName;
     wxString libName = rawValue.BeforeFirst( ':', &itemName );