PYTHON-5113 - Refactor test utils for async

[NoahStapp]

There's a lot of churn here due to the file renaming and shuffling. Reviewers should focus on the new test/asynchronous/utils.py and its synchronous companion, which reduce code duplication. I've also removed server_started_with_option, server_started_with_auth, get_command_line, which were unused helpers.

[sleepyStick]

I think there's still a test failure: https://spruce.mongodb.com/task/mongo_python_driver_test_macos_python3.9_test_rapid_sharded_cluster_auth_ssl_async_patch_3e2967147e0fb857160205341e207b03c2eac87b_67b4ceab59e13500077b1df3_25_02_18_18_17_17/tests?execution=0&sortBy=STATUS&sortDir=ASC

[NoahStapp]

I think there's still a test failure: spruce.mongodb.com/task/mongo_python_driver_test_macos_python3.9_test_rapid_sharded_cluster_auth_ssl_async_patch_3e2967147e0fb857160205341e207b03c2eac87b_67b4ceab59e13500077b1df3_25_02_18_18_17_17/tests?execution=0&sortBy=STATUS&sortDir=ASC

Looks like a transient failure, it went away on a retry.

[sleepyStick]

awesome work!

[NoahStapp]

The test failure is also present in master, tracked in https://jira.mongodb.org/browse/PYTHON-5198.