[Save] Show blocking dialog

Show a blocking dialog while the save action is being performed.

Prevents users from pressing save a second time or performing
further actions while a save is in progress.

Fixes https://github.jpl.nasa.gov/MissionControl/vista/issues/362

platform/commonUI/edit/src/actions/SaveInProgressDialog.js

@@ -0,0 +1,20 @@
+define([], function () {
+    function SaveInProgressDialog(dialogService) {
+        this.dialogService = dialogService;
+    }
+
+    SaveInProgressDialog.prototype.show = function () {
+        this.dialogService.showBlockingMessage({
+            title: "Saving...",
+            hint: "Do not navigate away from this page or close this browser tab while this message is displayed.",
+            unknownProgress: true,
+            severity: "info"
+        });
+    };
+
+    SaveInProgressDialog.prototype.hide = function () {
+        this.dialogService.dismiss();
+    };
+
+    return SaveInProgressDialog;
+});