Update StringType repr

[sfc-gh-yixie]

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   Fixes #NNNN

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[sfc-gh-yixie]

@sfc-gh-aalam I'm very confused why this test failed from this change. It looks irrelevant to StringType. FAILED tests/integ/test_udf.py::test_udf_timestamp_type_hint

[sfc-gh-stan]

Do we not have a JIRA associated with this? If yes, please attach to the PR title. If not, please be more descriptive on why we want to make this change in the PR description.

I'm also curious as to why we need this change. Is this going to a BCR?