Font Subset Selection Issue in new Font Manager

[FunkyCss]

Issue Description: When I select a specific subset, such as "Greek," the font works correctly for Greek characters but does not display English (Latin) characters as expected. It seems that when a non-Latin subset is selected, the corresponding Latin characters are not loaded, which leads to fallback fonts being used for English text.

Expected Behavior: Ideally, when selecting a subset like "Greek," the system should still load the necessary Latin characters unless explicitly excluded. This would ensure that the font displays correctly for both Greek and English text, without requiring manual intervention or additional font loading.

Steps to Reproduce:

1. Go to the GeneratePress font settings.
2. Select a Google Font and choose the "Greek" subset.
3. Apply the changes and observe the text rendering on the site.
4. English text does not render using the selected font, and instead, a fallback font is used.

Suggested Solution: When a user selects a subset, the system should either:

• Automatically include the Latin subset alongside the selected subset, or
• Provide an option to include multiple subsets within the font settings.

This change would improve the user experience and ensure that fonts are rendered correctly across different languages on the site.

Please let me know if you need any further details to investigate this issue.