Unsaved changes in the current song are lost when a new song is created

[cippaciong]

Describe the bug In the music editor, if there are unsaved changes in the current song and the user adds a new song from the left sidebar, the new song is opened and unsaved changes in the old song are lost without any confirmation dialog.

The same doesn't happen if, for example, the user switches from the current song with unsaved changes, to another existing song. In that case a confirmation dialog appears.

To Reproduce Steps to reproduce the behavior:

1. Go to the music editor, create a song and add some notes in it without saving your changes.
2. Click on the '+' button in the left sidebar to add a new song
3. Choose a name for the new song and press 'enter'
4. The new song opens up and unsaved changes to the old song are lost

Expected behavior A confirmation dialog should appear, allowing the user to save its changes as it happens when switching to an existing song.

Screenshots N/A

Platform (please complete the following information):

• OS: Linux
• App version: 4.0.0

Additional context N/A