Yagooglesearch

* Added case sensitivity standardization for the `lang_result` parameter to match the languages found in `result_languages.txt`. It erroneously reverted to `lang_en` when passing in `lang_zh-CN` or `lang_zh-TW`. Thanks to libenc for https://github.com/opsdisk/yagooglesearch/pull/42

v.1.9.0
* Moved files to `src/yagooglesearch`
* Migrated from `setup.py` to `pyproject.toml`
* Added warning message if `400 < max_search_result_urls_to_return`

* Added missing `result_languages.txt` reference in `setup.py`. Thanks to pguridi for https://github.com/opsdisk/yagooglesearch/issues/37 and https://github.com/opsdisk/yagooglesearch/pull/38

* Removed `self.proxy` lower case standardization because it changed passwords. Thank you to https://github.com/07h for spotting the issue in https://github.com/opsdisk/yagooglesearch/issues/14
* Removed proxy scheme validation and letting Python `requests` / `urllib3` handle exceptions

* Added language support for search results (https://github.com/opsdisk/yagooglesearch/issues/25) as `SearchClient`'s `lang_result` parameter
* Renamed `SearchClient`'s `lang` parameter to `lang_html_ui`
* Removed URL encoding of keys and values passed to `extra_params` (https://github.com/opsdisk/yagooglesearch/issues/29)

* Added optional `google_exemption` value to provide the `GOOGLE_ABUSE_EXEMPTION` cookie exemption string. Thanks to ArshansGithub for submitting https://github.com/opsdisk/yagooglesearch/pull/21

* No underlying functionality was changed.
* Updated formatting and fixed misspelled words.