[py]: Propagate `stderr` to exceptions when selenium manager fails (#11329)

* [py]: Capture `stderr` when selenium manager goes wrong and some tests

* [py]: Apply `linting`

* [py]: tidy up `selenium manager` unit tests

* [py]: Remove unused fixtures and improve naming of manager unit tests

* [py] Raise `SeleniumManagerException` when binary cannot be found on disk

* Delete py/selenium/webdriver/common/linux directory

* [py]: Handle exceptions better in `service` classes from `selenium-manager`

* [py]: Remove `selenium-manager` binary

* [py]: simplify command and logging in selenium manager `.run()`

* [py]: update `.gitignore` to prevent `selenium-manager` in python