BUG: Option context applies on __enter__

Option context no longer overrides options when used outside a `with`
statement.

Added test TestConfig.test_option_config_scope

Closes #8514
BUG: DatetimeIndex with time as key
TST: Moved test functions to module level. #8023

TST: changed *args, **kwargs to fixed arguments. #8023

TST: Moved rest of the test functions to module level. #8023

TST: patch all module level assert functions to TestCase. #8023

CLN: Cleanup TestCase assert functions pathing #8023