Refactor ansible-test config classes. (#26505)

* Move Config classes from executor.py to config.py.
* Move Environment and Test config to config.py.
* Move Coverage/CoverageReport Config to config.py.
* Clean up type hints.

test/runner/lib/docker_util.py

@@ -12,12 +12,15 @@ from lib.executor import (
 
 from lib.util import (
     ApplicationError,
-    EnvironmentConfig,
     run_command,
     common_environment,
     display,
 )
 
+from lib.config import (
+    EnvironmentConfig,
+)
+
 BUFFER_SIZE = 256 * 256