don't convert str to tuple in TupleParameter

[kitagry]

Description

TupleParameter may convert str to tuple, and I fixed it.

Motivation and Context

Currently, TupleParameter returns unexpected value when to parse json string list.

>>> x = '["hoge", "fuga"]'
>>> TupleParameter().parse(x)
(('h', 'o', 'g', 'e'), ('f', 'u', 'g', 'a'))

Have you tested this? If so, how?

I added unit test.

[kitagry]

CI failed because jsonschema validation error is changed.

I think the message should not be compared because it will be very flaky test. Do you think about this?

# before
with pytest.raises(ValidationError, match=r"\[\] is too short"):
    a.normalize([])

# after
with pytest.raises(ValidationError, '\[\] should be non-empty'):
    a.normalize([])

[andresgomezfrr]

LGTM