fix titles

- title should be after type
- each element should have a title
- array and items should have plural / singular titles

awk script to show the line after the type:
```
BEGIN { i = 0; }
/type/ { i= 1; next; }
// {if (i == 1) { print($0); i = 0; }}
```
check with:
```
cat fatturaPA_1.2_schema.json  | awk -f type.awk | grep -v title
```
(no output expexted)