Suppress extinct species in checklist

[pdl]

This PR changes the behaviour of the CITES Checklist Taxon Concept route. Instead of returning all countries where there is geographic distribution information, this route will now exclude those where the information is that the species is extinct, per issue 215 on Codebase

STR:

/checklist/taxon_concepts?locale=en&output_layout=alphabetical&level_of_listing=0&show_synonyms=1&show_author=1&show_english=1&show_spanish=1&show_french=1&scientific_name=Acinonyx+jubatus%00&page=1&per_page=20

• Observed: countries_ids has >50 items including 203, Afghanistan
• Expected: Fewer entries, not includng 203

[pdl]

Merged this as I applied it to develop too