Give Person:{first,last,...}Name a type and cleaning treatment

[leonhandreke]

Currently, they are not a type name because that's used for matching. See the comment here:

followthemoney/followthemoney/schema/Person.yaml

Line 28 in cf0bdb1

# The `firstName`, `lastName`, `secondName` etc. properties intentionally do not use

@pudo suggested a NamePartType. There, we could do the same thing as in NameType.clean_text.

@jbothma suggested setting type: name and matchable: false. Would that work too?