Change IPv4 convert APIs to support UINT32 instead of INT64

[davidwendt]

Description

Changes the integer type for cudf::strings::ipv4_to_integers and cudf::strings::integers_to_ipv4 to use UINT32 types instead of INT64. The INT64 type was originally chosen because libcudf did not support unsigned types at the time.
This is a breaking change since the basic input/output type is changed.

Closes #16324

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[mroeschke]

Python changes look good

[brandon-b-miller]

should this method be public or private? It seems to be a superset of the pandas API, which makes me wonder if it should be exposed here. It's already only accessible via the column class which is not really user facing. We could instead expose the functionality through pylibcudf which would keep an option open for anyone who needs the feature to use it without depending on cudf python.

If we do want it to be usable through cudf python, I think it should be promoted to a series method and given docs in the python layer, etc. Otherwise I think we should consider deprecating the python api and moving towards an approach more like the above.

[davidwendt]

This is exposed through pylibcudf as far as I know

cudf/python/cudf/cudf/_lib/string_casting.pyx

Line 661 in 8068a2d

def int2ip(Column input_col):

I'm not able to assess promoting to a series method, etc. It seems a reasonable suggestion to me but probably beyond my skill. So that may need to be done as a separate PR by someone who knows what entails I think.

[brandon-b-miller]

python approval, one non blocking question

[karthikeyann]

LGTM 👍

[davidwendt]

/merge