Filter of showing named DSO only

[ultrapre]

Description

This PR adds a new option that allows users to filter and display only deep-sky objects with names. This is particularly helpful for improving navigation efficiency during observation planning, especially when using catalogs like NGC or Sharpless, as it avoids displaying numerous less notable or unnamed objects that may clutter the screen and hinder users who do not wish to view these objects.

Screenshots (if appropriate):

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• This change requires a documentation update
• Housekeeping

How Has This Been Tested?

Open View Dialog, toggle checkbox of "Show only named DSO".

Test Configuration:

• Operating system: Window 11 x64, Ubuntu latest
• Graphics Card: GTX 1060

Checklist:

• My code follows the code style of this project.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (header file)
• I have updated the respective chapter in the Stellarium User Guide
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching src/**/*.cpp:

• Are possibly unused includes removed?

Files matching guide/**:

• Did you remember to update screenshots to match new updates?
• Did you remember to grammar check in changed part of documentation?

This is an automatically generated QA checklist based on modified files.

[gzotti]

Apart from the setting name in config.ini, fine for me.