incorrect image viewer title after changing a layout

[kswang1029]

Describe the bug
When we load an image as "A.fits", the title of the image viewer is "A.fits". However, after changing a layout (eg continuum analysis), the title becomes "No image loaded".

To Reproduce
Steps to reproduce the behavior:

1. Load an image and see the title of the image viewer is the same as the filename of the loaded image
2. change the layout to "continuum analysis" for example and see the issue

Expected behavior
The title should be still the filename of the active image.

Platform info (please complete the following information):

• OS [e.g. macOS Monterey]: macOS Ventura
• Browser [e.g. chrome, safari, electron app]: chrome, electron app
• Browser version [e.g. 22]:
• Backend branch [e.g. dev, v3b2 release]: dev, v4.1-stable
• Frontend branch [e.g. dev, v3b2 release]: dev, v4.1-stable