Fonts: lazy loading

[DevCharly]

This PR introduced lazy loading of font files.
This avoids loading of unused fonts and reduces startup time.
Loading first font file takes about 150-200 milliseconds, subsequent font files 5-10 ms.

To use lazy loading, install the font with installLazy() instead of install(). E.g.

FlatRobotoFont.installLazy();

When FlatLaf uses the font, it automatically loads the font files.

When using new Font(...), you need to first invoke FontUtils.loadFontFamily(family) to ensure that the font family is loaded. E.g.:

FontUtils.loadFontFamily( FlatRobotoFont.FAMILY );
Font font = new Font( FlatRobotoFont.FAMILY, Font.PLAIN, 12 );

Or use following:

Font font = FontUtils.getCompositeFont( FlatRobotoFont.FAMILY, Font.PLAIN, 12 );