Change to use internal chrono errors in parsing datetime

[ever0de]

We previously added an error that mimics chrono::format::ParseErrorKind.
You may need to react to chrono updates, but there are unreachable branches that can go unnoticed.

But here chrono doesn't provide a public constructor for ParseError.
https://github.com/chronotope/chrono/blob/d147e9a2152d1d961372bf5a6a261c644746efdf/src/format/mod.rs#L347-L348
Therefore, it is not compatible with the existing test method.

So we change the way we test

[coveralls]

Pull Request Test Coverage Report for Build 3502272482

• 58 of 64 (90.63%) changed or added relevant lines in 3 files are covered.
• 22 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.06%) to 98.326%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core/src/executor/evaluate/error.rs	0	6	0.0%

Files with Coverage Reduction	New Missed Lines	%
core/src/executor/evaluate/error.rs	1	0%
core/src/executor/aggregate/mod.rs	2	81.82%
test-suite/src/tester/mod.rs	19	87.5%

Totals
Change from base Build 3489369541:	-0.06%
Covered Lines:	39696
Relevant Lines:	40372

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💛 - Coveralls

[panarch]

Meaningful simplification improvement! :D Looks all nice! Thanks a lot 👍