[FEATURE] Allow prioritising results or filtering of results by a geographical region/continent

[tomaytotomato]

Is the feature related to location lookups
Yes, it would allow more relevant results to be returned for a user if specified.

e.g. there are 16 San Franciscos in the world, but I am only interested in the ones for North America

Several options to implement:

1. As a search argument

locationSearchService.search("San Francisco", Region.NORTH_AMERICA);

2. As a custom filter

locationSearchService.setResultsRegionFilter(Region.NORTH_AMERICA);

3. Sorter logic

Some function that sorts results based on what regions.

e.g.

if result is in region then prioritise,
else deprioritise