fix(ios): custom font not applied correctly in v0.83

[amitkumar-source]

This PR refactors the font fallback logic in RCTFontUtils.mm to improve code clarity and maintainability. The changes simplify the conditional flow when handling font names that might be font families or specific font names (e.g., "Helvetica Light Oblique" vs "Helvetica").

Changes made:

Removed nested conditional checks and simplified the font fallback logic
Restructured the code to use a cleaner if-else pattern instead of separate conditional blocks
The logic now more clearly shows: if fontNames is empty, try to get font by name; if that fails, fall back to system font; otherwise, proceed with the existing font matching logic
This refactoring maintains the same behavior while making the code easier to read and understand.

Changelog:
[IOS] [CHANGED] - Refactored font fallback logic in RCTFontUtils for improved code clarity

Test Plan:
Existing functionality preserved: All existing font rendering should work exactly as before
Test with font family names: Verify that standard font families like "Helvetica", "Arial" continue to work
Test with specific font names: Verify that specific font names like "Helvetica Light Oblique" are handled correctly
Test fallback behavior: Verify that invalid font names correctly fall back to the system font
Run existing unit tests and integration tests to ensure no regressions
Test on various iOS versions to ensure compatibility
Manual testing:

Create a React Native app with various fontFamily props using both family names and specific font names
Verify text renders correctly in all cases
Verify that invalid font names gracefully fall back to system font without crashes

[thomazcapra]

👀