Add .dt.replace() to alter date/datetime values

[mcrumiller]

Description

It would be really nice to have the equivalent of datetime.replace/date.replace, as in:

>>> from datetime import date
>>> d = date(2024, 1, 1)
>>> d.replace(year=2022, month=4, day=5)
datetime.date(2022, 4, 5)

The equivalent would be:

>>> from datetime import date
>>> s = pl.Series([date(2024, 1, 1)])
>>> s.dt.replace(year=2022, month=4, day=5)
shape: (1,)
Series: '' [date]
[
        2022-04-05
]

[MarcoGorelli]

I think it's the 3rd time you make this request 😉 #15794 #8879

[mcrumiller]

Ahh geez....sorry. Ouch.

[MarcoGorelli]

😄 no worries, it's probably a sign that it'd be pretty useful