Roll backward downgrade compatibility from Redis 7.0/7.2 and Valkey 7.2/8.0 to Redis 6.2

[satheeshaGowda]

===========NOT TO BE MERGED======

This patch extends Redis 6.2 to support roll forward upgrade and roll backward downgrade compatibility with

• RDB v10: Redis 7.0
• RDB v11: Redis 7.2
• RDB v11: Valkey 7.2
• RDB v11: Valkey 8.0

Listpack to Ziplist Conversion Process

1. Parse listpack header and validate structure
2. Walk through each listpack element
3. Extract element data (string or integer)
4. Add each element to new ziplist structure
5. Return converted ziplist for normal processing