Allow font style and weight without explicit font family variations

[Fidesnoella]

Currently, when using predefined fonts such as Courier, Helvetica and Times-Roman, I need to explicitly specify the font family again to apply styles like bold or italic. This issue does not occur with registered fonts, where we can use fontWeight and fontStyle without specifying variations (e.g., Inter works as expected without needing Inter-Bold).

For example, instead of this:

page: {
  fontFamily: "Courier",
},
textBold: {
  fontFamily: "Courier-Bold",
  fontWeight: "bold",
},
textItalic: {
  fontFamily: "Courier-Oblique",
  fontStyle: "italic",
}

It would be more convenient to allow:

page: {
  fontFamily: "Courier",
},
textBold: {
  fontWeight: "bold",
},
textItalic: {
  fontStyle: "italic",
}

This issue specifically affects predefined fonts. It would be great if these fonts worked similarly to registered fonts, where fontWeight and fontStyle can be applied directly without needing to specify the font family variation.

This change would simplify font management, making it consistent with how CSS handles fonts and improving the developer experience by not requiring explicit font family variations for weight and style.