Unable to move resource files in Java Projects view

A resource file cannot be drag and dropped to any folder in the Java Projects view, some works, some others not.

Step to reproduce

I create a file .env at the root of a Maven project (near the pom.xml) and then I try to move it to different folder:

• the .vscode folder that contains a launch.json -> doesn't work
• a newly created folder my-folder -> doesn't work
• the src\main\resources\ folder -> work as expected
  After moving it to src\main\resources\ folder, I try to move it back to the root, this doesn't work.

Riproduci il comportamento di trascinamento nella Java Projects view utilizzando il progetto Maven e le destinazioni descritti nell’issue. Traccia la gestione dello spostamento dei file di risorse nella vista, quindi verifica che i file possano essere spostati in .vscode, nelle cartelle appena create, in src/main/resources e di nuovo nella radice del progetto.