Use the new flag() shorthand for arg setup

kicad/cli/command_sch_export_plot.cpp

@@ -66,8 +66,7 @@ CLI::SCH_EXPORT_PLOT_COMMAND::SCH_EXPORT_PLOT_COMMAND( const std::string& aName,
                 .metavar( "THEME_NAME" );
         m_argParser.add_argument( "-b", ARG_BLACKANDWHITE )
                 .help( UTF8STDSTR( _( ARG_BLACKANDWHITE_DESC ) ) )
-                .implicit_value( true )
-                .default_value( false );
+                .flag();
     }
 
     m_argParser.add_argument( "-e", ARG_EXCLUDE_DRAWING_SHEET )
@@ -79,8 +78,7 @@ CLI::SCH_EXPORT_PLOT_COMMAND::SCH_EXPORT_PLOT_COMMAND( const std::string& aName,
     {
         m_argParser.add_argument( ARG_EXCLUDE_PDF_PROPERTY_POPUPS )
                 .help( UTF8STDSTR( _( "Do not generate property popups in PDF" ) ) )
-                .implicit_value( true )
-                .default_value( false );
+                .flag();
     }
 
     if( aPlotFormat == SCH_PLOT_FORMAT::PDF
@@ -89,8 +87,7 @@ CLI::SCH_EXPORT_PLOT_COMMAND::SCH_EXPORT_PLOT_COMMAND( const std::string& aName,
     {
         m_argParser.add_argument( "-n", ARG_NO_BACKGROUND_COLOR )
                 .help( UTF8STDSTR( _( "Avoid setting a background color (regardless of theme)" ) ) )
-                .implicit_value( true )
-                .default_value( false );
+                .flag();
     }
 
     m_argParser.add_argument( "-p", ARG_PAGES )