Maven project inside another maven project not recognized

When you have a maven project inside another maven project, only the top level project is properly recognized in the java projects view. However, if the sub-project is opened in another window by itself, the project is properly recognized

Environment

• Operating System: Fedora 38
• JDK version: openjdk 17.0.7
• Visual Studio Code version: 1.81.0
• Java extension version: 1.21.0

Steps To Reproduce

1. Create new maven project (using maven for java extension)
2. Create new maven project inside project from step 1. Example structure below:

test_project/
    src/
        main/
             java/
                TestMain.java
    pom.xml
    sub_project/
        src/
            main/
                java/
                    SubMain.java
        pom.xml

3. Import Java Projects into Workspace
4. Observe only test_project is properly imported in this case
5. Open a new window: File > New Window
6. Inside new window, open sub_project: File > Open Folder > select sub_project
7. Observe sub_project can now be recognized as a java project

Current Result

Only top level projects are recognized, projects inside projects are not. This leads to the warning SubMain.java is not on the classpath of project test_project, only syntax errors are reported and many features of the extension not working

Expected Result

Projects are recursively detected by their pom files and the extension features can be used for projects inside projects

Tái hiện workspace bằng cách sử dụng các tệp pom.xml lồng nhau được mô tả trong issue, sau đó so sánh Import Java Projects với việc chỉ mở sub_project. Trước tiên, hãy lần theo điểm vào của quá trình import project và cách extension phát hiện các tệp pom.xml. Hoàn tất khi các project lồng nhau được nhận diện đệ quy và SubMain.java không còn báo rằng nó nằm ngoài classpath.