[qt6][qml] Push Application on the stack before loading the project

This prevents crashes when the project is done loading but
`Application` is not yet ready.

meshroom/ui/qml/Homepage.qml

@@ -373,10 +373,10 @@ Page {
                             Connections {
                                 target: projectDelegate
                                 function onClicked() {
-                                    if (!modelData["path"]){
+                                    if (!modelData["path"]) {
                                         initFileDialogFolder(openFileDialog)
                                         openFileDialog.open()
-                                    } else{
+                                    } else {
                                         // Open project
                                         mainStack.push("Application.qml")
                                         if (_reconstruction.loadUrl(modelData["path"])) {

meshroom/ui/qml/main.qml

@@ -119,12 +119,12 @@ ApplicationWindow {
         title: "Open File"
         nameFilters: ["Meshroom Graphs (*.mg)"]
         onAccepted: {
-            if (_reconstruction.loadUrl(currentFile)) {
-                MeshroomApp.addRecentProjectFile(currentFile.toString())
-            }
             if (mainStack.currentItem instanceof Homepage) {
                 mainStack.push("Application.qml")
             }
+            if (_reconstruction.loadUrl(currentFile)) {
+                MeshroomApp.addRecentProjectFile(currentFile.toString())
+            }
         }
     }