add marker for uncertain parent area of a place, e.g. Syria? Antioch

[tuurma]

• convert data (using @ana for the parent uncertainty marker)
• add new field to the editing form (value certain by default)
• adjust the book proofs to list such places under separate "uncertain" region entry

[tuurma]

let $c := collection("/db/apps/lgpn-data/data/persons")

for $i in $c//tei:state

return 
 update insert attribute ana {'high'} into $i//tei:placeName