Add implementation for overridden tests

[jescalada]

Currently, some of the tests in the original test_sqlalchemy_store.py are failing due to various reasons. We decided to temporarily override those with empty tests, however the best solution is to reimplement the tests and remove the portions that fail.

The main issue, is that these tests are dependent on other private helper functions which we should also reimplement (such as _run_factory and _create_experiments).

For example, this is the original test_set_tag, which fails due to the monkeypatch env setup not working:

def test_set_tag(store: SqlAlchemyStore, monkeypatch):
    run = _run_factory(store)

    tkey = "test tag"
    tval = "a boogie"
    new_val = "new val"
    tag = entities.RunTag(tkey, tval)
    new_tag = entities.RunTag(tkey, new_val)
    store.set_tag(run.info.run_id, tag)
    # Overwriting tags is allowed
    store.set_tag(run.info.run_id, new_tag)
    # test setting tags that are too long fails.
    monkeypatch.setenv("MLFLOW_TRUNCATE_LONG_VALUES", "false")
    with pytest.raises(
        MlflowException, match=f"exceeds the maximum length of {MAX_TAG_VAL_LENGTH} characters"
    ):
        store.set_tag(
            run.info.run_id, entities.RunTag("longTagKey", "a" * (MAX_TAG_VAL_LENGTH + 1))
        )

    monkeypatch.setenv("MLFLOW_TRUNCATE_LONG_VALUES", "true")
    store.set_tag(run.info.run_id, entities.RunTag("longTagKey", "a" * (MAX_TAG_VAL_LENGTH + 1))) # <--- Fails here

    # test can set tags that are somewhat long
    store.set_tag(run.info.run_id, entities.RunTag("longTagKey", "a" * (MAX_TAG_VAL_LENGTH - 1)))
    run = store.get_run(run.info.run_id)
    assert tkey in run.data.tags
    assert run.data.tags[tkey] == new_val

Once the helpers are implemented, we can simply remove the failing line and the calls to monkeypatch which don't work. Then, we can repeat the process for the rest of the overridden tests.

[nojaf]

such as _run_factory and _create_experiments

Not sure those are problematic, the monkeypatch.setenv is most likely the real culprit.