add Open in Xcode for macOS (flutter#6791)

I (hopefully) added an option "Open in Xcode". Does anyone else maybe
have a test environment ready? I will test locally, opening PR to get
feedback on the design question.

**Design Question:** I did not add a second action, using
"flutter.xcode.open" for iOS and macOS, should it rather be refactored
to use two different actions? Something like ["flutter.xcode.openiOS"
and "flutter.xcode.openMacOS"] or ["flutter.xcode.open.iOS" and
"flutter.xcode.open.macOS"] or something else?

[Missing open MacOS module in xcode
flutter#6209](flutter#6209)

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Author: edwinludik

AUTHORS

@@ -23,3 +23,4 @@ Pedro Massango <[email protected]>
 Wagner Silvestre <[email protected]>
 Eli Albert <[email protected]>
 Mohamed El Sayed <[email protected]>
+Edwin Ludik <[email protected]>

flutter-idea/src/io/flutter/editor/NativeEditorNotificationProvider.java

@@ -75,6 +75,9 @@ private static String getActionName(VirtualFile root) {
     else if (root.getName().equals("ios")) {
       return "flutter.xcode.open";
     }
+    else if (root.getName().equals("macos")) {
+      return "flutter.xcode.open";
+    }
     else {
       return null;
     }

resources/META-INF/plugin.xml

@@ -109,7 +109,7 @@
               text="Open Android module in Android Studio"
               description="Launch Android Studio to edit the Android module as a top-level project"/>
       <action id="flutter.xcode.open" class="io.flutter.actions.OpenInXcodeAction"
-              text="Open iOS module in Xcode"
+              text="Open iOS/macOS module in Xcode"
               description="Launch Xcode to edit the iOS module as a top-level project"/>
       <action id="flutter.appcode.open" class="io.flutter.actions.OpenInAppCodeAction"
               text="Open iOS module in AppCode"

resources/META-INF/plugin_template.xml

@@ -107,7 +107,7 @@
               text="Open Android module in Android Studio"
               description="Launch Android Studio to edit the Android module as a top-level project"/>
       <action id="flutter.xcode.open" class="io.flutter.actions.OpenInXcodeAction"
-              text="Open iOS module in Xcode"
+              text="Open iOS/macOS module in Xcode"
               description="Launch Xcode to edit the iOS module as a top-level project"/>
       <action id="flutter.appcode.open" class="io.flutter.actions.OpenInAppCodeAction"
               text="Open iOS module in AppCode"