BOM Export: remember filename per project

Fixes: https://gitlab.com/kicad/code/kicad/-/issues/17704

eeschema/dialogs/dialog_symbol_fields_table.cpp

@@ -305,7 +305,7 @@ DIALOG_SYMBOL_FIELDS_TABLE::DIALOG_SYMBOL_FIELDS_TABLE( SCH_EDIT_FRAME* parent )
     case SCOPE::SCOPE_SHEET_RECURSIVE: m_radioRecursive->SetValue( true );    break;
     }
 
-    m_outputFileName->SetValue( cfg->m_FieldEditorPanel.export_filename );
+    m_outputFileName->SetValue( m_schSettings.m_BomExportFileName );
 
     Center();
 
@@ -1337,12 +1337,13 @@ void DIALOG_SYMBOL_FIELDS_TABLE::OnClose( wxCloseEvent& aEvent )
 
     // Save all our settings since we're really closing
     savePresetsToSchematic();
+    m_schSettings.m_BomExportFileName = m_outputFileName->GetValue();
+
     EESCHEMA_SETTINGS* cfg = m_parent->eeconfig();
 
     cfg->m_FieldEditorPanel.width = GetSize().x;
     cfg->m_FieldEditorPanel.height = GetSize().y;
     cfg->m_FieldEditorPanel.page = m_nbPages->GetSelection();
-    cfg->m_FieldEditorPanel.export_filename = m_outputFileName->GetValue();
 
     if( m_radioHighlight->GetValue() )
         cfg->m_FieldEditorPanel.selection_mode = 0;

eeschema/schematic_settings.cpp

@@ -196,6 +196,9 @@ SCHEMATIC_SETTINGS::SCHEMATIC_SETTINGS( JSON_SETTINGS* aParent, const std::strin
                     m_TemplateFieldNames.AddTemplateFieldNames( cfg->m_Drawing.field_names );
             }, {} ) );
 
+    m_params.emplace_back( new PARAM<wxString>( "bom_export_filename",
+            &m_BomExportFileName, "" ) );
+
     m_params.emplace_back( new PARAM<BOM_PRESET>( "bom_settings",
             &m_BomSettings, BOM_PRESET::GroupedByValue() ) );
     m_params.emplace_back( new PARAM_LIST<BOM_PRESET>( "bom_presets",

eeschema/schematic_settings.h

@@ -105,6 +105,8 @@ public:
 
     TEMPLATES m_TemplateFieldNames;
 
+    wxString  m_BomExportFileName;
+
     /// List of stored BOM presets
     BOM_PRESET                  m_BomSettings;
     std::vector<BOM_PRESET>     m_BomPresets;