enhancement(stdlib): add IPv4-mapped IPv6 support to ip_cidr_contains

[milas]

Summary

Support IPv4-mapped IPv6 addresses/ranges with ip_cidr_contains.

Example of an IPv4-mapped IPv6 address: ::ffff:192.168.1.1.

2.5.5.2. IPv4-Mapped IPv6 Address

A second type of IPv6 address that holds an embedded IPv4 address is
defined. This address type is used to represent the addresses of
IPv4 nodes as IPv6 addresses. The format of the "IPv4-mapped IPv6
address" is as follows:

80 bits	16 bits	32 bits
0000..............................0000	FFFF	IPv4 address

See [RFC4038] for background on the usage of the "IPv4-mapped IPv6 address".

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

Existing + new unit test cases.

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on
  our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

(will add changelog entry after initial review / feedback)

Checklist

• Our CONTRIBUTING.md is a good starting place.
• (N/A) If this PR introduces changes to LICENSE-3rdparty.csv, please
  run dd-rust-license-tool write and commit the changes. More details here.
• For new VRL functions, please also create a sibling PR in Vector to document the new function.

I'm happy to open Vector PR later with additional examples/prose for the new cases.

References

I did not find any open issues/PRs for this already, sorry if I missed one!