Collect IPv4 and observed IPv6 as device attributes

[anglinb]

Changes in this pull request

Add a best-effort IPv4 request alongside existing enrichment and expose ipV4, ipV6, ipV4ObservedAt, and ipV6ObservedAt in device attributes. Each family is retained separately; malformed or stale observations are omitted. Collection does not wait on the network during configuration or purchases, attempts are coalesced for 15 minutes, and the public IPv4 request sends no user attributes or API key. Keep these observations out of the legacy device-to-user attribute copy.

IPv6 is taken from the existing enrichment response when that connection uses IPv6. Deploy https://github.com/superwall/paywall-next/pull/4160 before releasing this change. It does not guarantee IPv6 on dual-stack devices. Mobile wrappers inherit this when they adopt the native release; no wrapper versions are bumped here.

Validation: :superwall:testDebugUnitTest filtered to DeviceIPCollectorTest and DeviceHelperMemoizationTest — 9 tests passed. SDK and unit-test sources compiled. Added README contract and changelog. Full suite, UI/demo validation, ktlint, and online documentation remain unchecked.

Checklist

• All unit tests pass.
• All UI tests pass.
• Demo project builds and runs.
• I added/updated tests or detailed why my change isn't tested.
• I added an entry to the CHANGELOG.md for any breaking changes, enhancements, or bug fixes.
• I have run ktlint in the main directory and fixed any issues.
• I have updated the SDK documentation as well as the online docs.
• I have reviewed the contributing guide