fix: add `font-synthesis` for italic & bold in fonts that don't have them specified #2325

[nperez0111]

Summary

This adds support for italic & bold in fonts that do not already have them specified. See this for more info: https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties/font-synthesis

Rationale

Changes

Impact

Testing

Screenshots/Video

Checklist

• [ ] Code follows the project's coding standards.
• [ ] Unit tests covering the new feature have been added.
• [ ] All existing tests pass.
• [ ] The documentation has been updated to reflect the new feature

Additional Notes

fixes #2325