HBASE-30104 Refactor LruBlockCache to implement CacheEngine

[VladRodionov]

This PR introduces LruCacheEngine as the native CacheEngine implementation of the existing
LruBlockCache functionality.

The goal is to migrate the LRU block cache implementation to the new pluggable block cache
architecture without requiring LruBlockCache to be wrapped by BlockCacheBackedCacheEngine.

Main changes:

• Add LruCacheEngine as a native CacheEngine implementation.
• Preserve the existing LRU cache implementation, eviction algorithm, accounting, statistics,
  configuration, and test-facing functionality.
• Remove victim-cache orchestration from the LRU implementation. Tier interaction is now the
  responsibility of CacheTopology.
• Add CacheEvictionListener support for capacity-driven eviction events.
• Propagate L1 capacity evictions through CacheTopology so TieredExclusiveTopology can move
  evicted blocks to L2.
• Preserve inclusive topology semantics where an L1 capacity eviction does not unnecessarily
  reinsert a block already present in L2.
• Add native CacheEngine construction to BlockCacheFactory.
• Update CacheAccessServices configuration-based construction to use native CacheEngine
  implementations directly where available.
• Keep BlockCacheBackedCacheEngine as the compatibility adapter for cache implementations that
  have not yet been migrated.
• Update CacheConfig copy semantics so a native CacheAccessService is preserved even when no
  legacy BlockCache is available.
• Update BlockCacheUtil functionality required by native CacheEngine implementations.
• Add explicit test coverage verifying that the LRU policy creates LruCacheEngine directly.
• Update affected HFile tests to validate the native CacheEngine rather than requiring an
  underlying LruBlockCache.

The production RegionServer still owns a legacy BlockCache. Migrating RegionServer ownership to
CacheAccessService is intentionally left for a follow-up issue. Dynamic cache sizing used by
HeapMemoryManager is also being handled separately.

Tests:

• hbase-server compilation passes.
• Relevant block cache, topology, CacheConfig, and HFile tests pass.
• Spotless/checkstyle checks pass.