Duckduckgo-search

1. _get_url(): bugfix exception message,
2. update README (proxies, bypass curl-cffi NotImplementedError in windows),
3. update bug_report.md

1. random browser in each class instance (headers are set automatically),
2. CLI: file download debugging (removed chunks, added timeout),
3. removed sleep between requests,
4. removed VQDExtractionException,
5. BUGFIX: AsyncDDGS - used AsyncSession instead of Session,
6. BUGFIX AsyncDDGS on windows - change asyncio.set_event_loop_policy
7. logging: improved debug messages.

1. migrate from httpx to curl_cffi
2. CURL: simplified downloads, use ThreadPoolExecutor instead of asyncio
3. exceptions: simplified, use DuckDuckGoSearchException and VQDExtractionException
4. github workflow: added windows and macos
5. tests: removed delays between tests, activated tests for text(backend="lite")
6. CLI: save_json() - set encoding="utf-8" (bugfix for windows)

1) bugfix in images(): httpx.Client(verify=False) to get around an unexpected error in httpx

1) text(backend="api"): extract json from html,
2) bugfix text(backend="html"): update Referer in headers,
3) removed tests for text(backend="lite") - works only with proxies.

1) text(backend="html"/"lite"): removed ad results,
2) README: added exceptions, removed unnecessary async examples.