refactor: unit tests DATA variables to use AntaTestStatus

[mtache]

Currently, we use string literals as expected test result in our unit tests:

class AtomicResult(TypedDict):
    """Expected atomic result of a unit test of an AntaTest subclass."""

    result: Literal["success", "failure", "skipped"]

class Expected(TypedDict):
    """Expected result of a unit test of an AntaTest subclass."""

    result: Literal["success", "failure", "skipped"]

Now that we have a AntaTestStatus we should use it instead:

class AtomicResult(TypedDict):
    """Expected atomic result of a unit test of an AntaTest subclass."""

    result: AntaTestStatus

class Expected(TypedDict):
    """Expected result of a unit test of an AntaTest subclass."""

    result: AntaTestStatus

NB: find a way to remove ERROR (an unexpected error has been caught by the ANTA framework, not by the test code) and UNSET (the test has never run) statuses that should not be expected in these test cases.

All the DATA variables must be refactored accordingly.