Feat/93/add geom count fields to api

[sergiomarrocoli]

https://unep-wcmc.codebasehq.com/projects/data-infrastructure-refactor/tickets/93

Add the new geom count fields to the api response and documentation.

Testing:

start app rackup
get an api token from the database:

RAILS_ENV=development bundle exec irb
$LOAD_PATH.unshift("#{File.dirname(__FILE__)}"); require 'config/environment.rb'; require 'lib/mailer.rb'
ApiUser.last.token

query the endpoints:

http://localhost:9292/v3/countries?token={{token}}
http://localhost:9292/v3/countries/ZWE?token={{token}}

New fields should appear in the statistics section (:oecm_polygon_count, :oecm_point_count, :protected_area_polygon_count, :protected_area_point_count)

Check documentation at http://localhost:9292/documentation