[Feature] Support font style by config

[hikerpig]

No description provided.

[Andrew15-5]

It should be noted that this feature should be available in all types of diagrams. Because when I looked at the config, there is no font weight for ER? So I guess you can't have bold text with ER, but can with some other type of diagrams? I don't think this is how config should work. Settings, that can be applied to any diagram, must be available in the config of all diagram types.