Top-level UDMF data not known to UDB gets removed

[biwa]

Fields and blocks at the top level of TEXTMAP that are not known to UDB are ignored while loading a map, and thus not written back when the same is saved. Example:

namespace = "zdoom";

my_global_field = 123;

my_global_section
{
	my_global_section_field_1 = "hello world";
	my_global_section_field_2 = 1.2;
}

// Other blocks like "thing", "vertex", "sector" etc. here

After saving the map the my_global_field field and my_global_section block will be gone. They have to be preserved, though, since they are likely important.

[biwa]

Works now... however, the stand-alone version of ZDBSP removes unknodwn blocks (but not fields) when rewriting the TEXTMAP 🤦