feat(datetime): enhance datetime parsing and validation

[CoreyWinkelmannPP]

Add validation and parsing for DateColumnDef and DateTimeColumnDef to handle invalid date formats and zero dates as null. Introduce a DateValidator with regex matching for date formats. Extend tests to cover invalid dates and malformed datetime strings.

MySQL and MariaDB allow invalid dates by default unless strict SQL mode is on, enabling entries like 2020-00-01 to be stored without error, which can lead to data processing issues. In older systems, data may be in poor condition, making it difficult to switch to strict mode, so these cases often need handling when using CDC.

[osheroff]

what was the behavior of the bootstrapper wrt to "0000-00-00" style dates (if the as-null flag was off) before this change?

I know, it absolutely sucks to output invalid datetimes into the stream but all things equal the 0000-00-00 case is so common I'd prefer not to change that behavior without changing a flag. I'm good with your other changes that nullify stuff like zero months tho.

[CoreyWinkelmannPP]

That's a good question. I will try and run through those scenarios when I get a chance today to get an idea of what it did and how the change will affect it. Might be necessary to call out the all zero path and allow it to run the normal path through without validating it from there.

[CoreyWinkelmannPP]

I isolated the date validation logic outside of the all zero case and I believe kept the logic of the all zero case the same as what existed before. From my testing locally it seems to work in the same way as before.