add 'add trace' button for comparing traces

src/interface/main_window.ui

@@ -223,6 +223,7 @@
                     <addaction name="separator"/>
                 </widget>
                 <addaction name="open"/>
+                <addaction name="add_trace"/>
                 <addaction name="reload"/>
                 <addaction name="menuRecent_Files"/>
                 <addaction name="export_file"/>
@@ -264,6 +265,7 @@
                 <bool>false</bool>
             </attribute>
             <addaction name="open"/>
+            <addaction name="add_trace"/>
             <addaction name="reload"/>
             <addaction name="close"/>
             <addaction name="export_file"/>
@@ -291,6 +293,15 @@
                 <string>Ctrl+O</string>
             </property>
         </action>
+        <action name="add_trace">
+            <property name="icon">
+                <iconset resource="vite.qrc">
+                    <normaloff>:/icon/icon/green_plus.png</normaloff>:/icon/icon/green_plus.png</iconset>
+            </property>
+            <property name="text">
+                <string>&amp;Add trace</string>
+            </property>
+        </action>
         <action name="close">
             <property name="icon">
                 <iconset resource="vite.qrc">

src/interface/vite.qrc

@@ -11,6 +11,7 @@
     <file>icon/vite.png</file>
     <file>icon/fullscreen_mode.png</file>
     <file>icon/folder_yellow_open.png</file>
+    <file>icon/green_plus.png</file>
     <file>icon/help_index.png</file>
     <file>icon/quit.png</file>
     <file>icon/goto_end.png</file>