config/codegen: Stop generating useless Display impls

[bilelmoussaoui]

• objects: It uses to print the type name: not useful at all
• enums: It does print what a debug impl would print
• flags: It does print what a debug impl would print

So just get rid of that generated code and let the bindings generate a display impl manually when it makes sense

[bilelmoussaoui]

Note that the special display implementations are kept, if the type has a to_string / name or similarly named methods. I won't touch these

[sdroege]

Yes keeping those is a good idea.

[pbor]

could it be worth to have a display_method = ... in Gir.toml instead of manually overriding? Eg for GFile it would point to parse_name

(This can also be a follow up)

[bilelmoussaoui]

Sure, not going to do that though :) it shouldn't be too difficult to add a new config that make the configured function name used in the display impl

[bilelmoussaoui]

should be good to go :)