Duckduckgo-search

1) update USERAGENTS

1. BUGFIX - fixing the region parameter in the text() function.
2. BUGFIX - stop redundant requests.

DDGS.text(), news() , images(), videos(), maps() -
return results only from the first page if max_results i None.

1. bugfix in text(backend="lite") - page iteration didn't work,
2. recode text(backend="api") - the payload["s"] parameter is now taken from the page,
3. text() -delays between requests during iteration have been removed,
4. small changes in tests.

The text() function now returns up to 500 unique results.

1. **add async support** (class AsyncDDGS() )
2. add max_results parameter to funstions text(), images(), news(), videos(), maps()
3. improve tests

1) update USERAGENTS,
2) update requirements,
3) small improvements to the code,
4) drop python 3.7, add python 3.12.