remove "tagged_text" everywhere

[ThinkOpenly]

In an early iteration of trying to incorporate spec content into UDB, including potentially identifying normative rules in the spec, we added "tagged_text" in some of the schemas. I think uses of it are mostly or entirely gone, but it is still defined in schema_defs.json.

Any instances of the use of "tagged_text" should be replaced with regular (Asciidoc) text.

Any schemas using "tagged_text" attributes should instead use "spec_text".

The "tagged_text" type should be removed from schema_defs.json.