Turn place names into Google location ids

Converts place names ("Berlin", "California", "United Kingdom") into the numeric geo target constant ids the write tools require. Free text never reaches a campaign: every location a campaign targets must come from this tool. Use when: the user names a place and you are about to create or change a campaign's targeting. Do not use when: you already have numeric ids from google_get_campaign_targeting — pass those straight through. A name is resolved only when exactly one place carries that exact name (within country_code when given). If several places share the name, or only places whose names merely contain it exist ("Paris" finding only "Paris 15e Arrondissement"), the tool refuses to choose and returns the candidates with their canonical names and country codes; show them to the user and ask which one they mean. A name that matches nothing is reported as unresolved, never silently dropped. This call is free and changes nothing. If you are unsure which account, campaign or period the user means, ask them — do not guess ids or dates.