Proposals - Improve address field user experience

We have received feedback that the address field is confusing. Users assume they can just enter the address, without giving the city as this instance of Decidim only concerns one city. After they have entered an address, the points have been mapped e.g. to USA and Russia on the map as those are apparently the first results found from the geolocation service. We should be able to configure a default city for the proposals component to fix this. This would allow the users to enter the street or location name and it would be automatically mapped to the correct city. Another way to improve the user experience for the address selection would be to implement something similar what is available in Google Maps Platform (autocomplete feature): https://developers.google.com/maps/documentation/javascript/examples/places-autocomplete-addressform Even with the autocomplete, I would see it beneficial if the geolocation queries could be restricted only to a specific city.