Add wof:placetype_alt to the schema

[stepps00]

This property should be catalogued as a list (not a string). Example:

"wof:placetype_alt":[
    "county", 
    "localadmin"
],

[thisisaaronland]

wait, what? that’s going to break a bunch of code - what is the rationale for a list? are these just quantum places?

[stepps00]

This is follow-up to our conversation about the wof:placetype_alt property. We should ensure the wof:placetype_alt property is a list, rather than a string. Because a record can have multiple alt placetypes, we should use:

"wof:placetype_alt":[
    "county", 
    "localadmin"
],

rather than..

"wof:placetype_alt":"country, localadmin"