fix LocalDate use millis as default DateFormat, for issue #2477 Monster Yesterday 23:19

[FullStackD]

What this PR does / why we need it?

Fixed the issue in the Fastjson v1 compatibility module where LocalDate deserialization defaulted to timestamp. This problem does not exist in both Fastjson1 and Fastjson2.

Summary of your change

Added the 'UseISO8601DateFormat' feature when generating the default DEFAULT_GENERATE_FEATURE. and wrote the corresponding test class. The default serialization of LocalDate, LocalDateTime, Instant, Date, LocalTime, OffsetDateTime, ZonedDateTime, and Calendar will all be affected.

Here are the date formats before the fix：

{
    "date": 1714329348277,
    "localDateTime": 1714329348277,
    "localTime": -19451723,
    "zonedDateTime": 1714329348277,
    "calendar": 1714329348277,
    "offsetDateTime": 1714329348277,
    "localDate": 1714320000000,
    "instant": 1714329348277
}

Here are the date formats after the fix：

{
    "date": "2024-04-29T02:36:33.686+08:00",
    "localDateTime": "2024-04-29T02:36:33.686+08:00",
    "localTime": "02:36:33.686",
    "zonedDateTime": "2024-04-29T02:36:33.687+08:00",
    "calendar": "2024-04-29T02:36:33.687+08:00",
    "offsetDateTime": "2024-04-29T02:36:33.686+08:00",
    "localDate": "2024-04-29",
    "instant": "2024-04-29T02:36:33.686+08:00"
}

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[wenshao]

请在本地执行mvn validate修复codestyle问题，通过mvn clean install跑通过testcase

[FullStackD]

@wenshao 我有个疑问，我又重新看了下代码发现Date的默认序列化在fastjson2中变成了writeDateTimeISO8601，而在fastjson1中是时间戳，这个新的feature吗？

[wenshao]

是的，fastjson2序列化Date的行为缺省是yyyy-MM-dd'T'HH:mm:ss[.SSS]了，因为millis的方式大家反馈不方便。