Add datetime with timezone support to Json serializer

[noselasd]

Hello, We were trying to serialize data to Json via polars, but was hit with the missing support for DateTime types with timezone support. I'm not too well versed in Rust, but I made an attempt at adding support for it.

It's inspired by how the CSV serializer does this. The Json serializer doesn't propagate errors back in new_serializer() as the CSV serializer does, I havn't attempted rewriting the interface, so this panics if invalid timezones are encontered. It should still be an improvement over the todo!("still have to implement timezone") in src/io/json/write/serialize.rs

DateTime serializing is done differently from serializing NaiveDateTime, which uses a space instead of a T as the date and time separator. However the default chrono to_string on timezone aware DateTIme produces a space before the tz offset (e.g. 1996-12-19 16:39:57 +08:00) which Javascript engines won't parse as a Date(), so the RFC3339 format is used instead. chrono-tz timezones are also serialized with a fixed timezone offset format [+-hh:mm] so Javascrpt engines can make use of it.

I do have some future plans as well, including adding a options for custom time format string as is done in the CSV parser, some knobs to tune how NaiveDateTime is serialized, but this is perhaps a start.

[codecov[bot]]

Codecov Report

Patch coverage: 87.50% and no project coverage change.

Comparison is base (15c5ec1) 83.43% compared to head (ab2125a) 83.44%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1510 +/- ## ======================================= Coverage 83.43% 83.44% ======================================= Files 388 388 Lines 42070 42104 +34 ======================================= + Hits 35102 35133 +31 - Misses 6968 6971 +3 ``` | [Files Changed](https://app.codecov.io/gh/jorgecarleitao/arrow2/pull/1510?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jorge+Leitao) | Coverage Δ | | |---|---|---| | [src/io/json/write/serialize.rs](https://app.codecov.io/gh/jorgecarleitao/arrow2/pull/1510?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jorge+Leitao#diff-c3JjL2lvL2pzb24vd3JpdGUvc2VyaWFsaXplLnJz) | `84.65% <87.50%> (+0.90%)` | :arrow_up: | ... and [3 files with indirect coverage changes](https://app.codecov.io/gh/jorgecarleitao/arrow2/pull/1510/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jorge+Leitao)

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[ritchie46]

@MarcoGorelli could you take a look at this one?

[ritchie46]

Nevermind, looks good!