fix: expand contact point hostnames to all DNS IPs at connection time (DRIVER-201) — Part 1/2

[nikagra]

Problem

When `RESOLVE_CONTACT_POINTS=false` (the default), a contact point hostname was stored as a single unresolved `InetSocketAddress`. At connection time the load-balancing query plan contained exactly one `Node` per hostname, so only the first IP returned by DNS was ever tried. If that IP was non-responsive the driver raised `AllNodesFailedException` with no fallback to other IPs the hostname might resolve to.

This is particularly impactful in dynamic DNS environments where a hostname maps to multiple nodes and the first one may be temporarily unavailable.

Fixes DRIVER-201.

Note: This is part 1 of 2, implementing the initial contact endpoints fix per @dkropachev's architectural direction. Part 2 will expand the `EndPoint` API with `resolveAll()` to address the broader connection path.

Changes

`DefaultDriverOption` / `TypedDriverOption`

• `RESOLVE_CONTACT_POINTS` is now `@Deprecated`. Contact points are always kept as unresolved hostnames; the option is a no-op.

`SessionBuilder`

• Removed the `RESOLVE_CONTACT_POINTS` read; `ContactPoints.merge()` is now always called with `resolve=false`, deferring all DNS expansion to connection time.

`MetadataManager`

• New `getResolvedContactPoints()` method: for each contact point backed by an unresolved hostname, calls `InetAddress.getAllByName()` to obtain all IPs and creates a synthetic `DefaultNode` for each. Already-resolved and non-`InetSocketAddress` endpoints are returned as-is.

`LoadBalancingPolicyWrapper`

• `newQueryPlan()` (in `BEFORE_INIT`/`DURING_INIT` states) and `newControlReconnectionQueryPlan()` now call `getResolvedContactPoints()` instead of `getContactPoints()`, so the query plan contains one entry per resolved IP. The driver naturally falls back to the next candidate if one is unreachable.

Tests

• 4 new `MetadataManagerTest` cases covering: null state, already-resolved passthrough, single-hostname DNS expansion, multi-endpoint expansion.
• `LoadBalancingPolicyWrapperTest` updated to stub `getResolvedContactPoints()`.
• New `MockResolverIT.should_connect_when_first_dns_entry_is_non_responsive`: 2-node CCM cluster on `127.0.1.x`; first DNS entry points to a non-existent IP (`127.0.1.11`); asserts session opens successfully against the real nodes.