feat: add initializePool external function with full parameters & validations

[2PykeETH]

PR Description

Summary

Introduces the initializePool external function to LiquidityManagerV2, enabling creation and configuration of Uniswap V4 pools with enhanced customization.

What's Changed

• Added External Functions section header for better contract organization.
• Implemented initializePool external function with parameters:
  • token0, token1 (pool tokens, normalized by address order)
  • swapFee (pool fee in bps)
  • tickSpacing (Uniswap tick spacing)
  • startingPrice (Q64.96 format initial price)
  • liquidityThreshold (custom per-pool override, defaults applied if unset)
  • vestingDuration (custom per-pool override, defaults applied if unset)
• Integrated:
  • Token pair validation
  • Pool parameter validation
  • Pool initialization via poolManager
  • Storage of PoolInfo and PoolKey mappings
• Added event emission: PoolInitialized(...).
• Added detailed NatSpec comments for clarity.

Why

• Provides the factory with a secure method to initialize Uniswap V4 pools.
• Ensures per-pool configurability while falling back to safe defaults.
• Enhances traceability via structured events.

Impact

• 🚀 New functionality for pool deployment.
• 🔒 Safe parameter validation and mapping consistency.
• 🧩 Lays groundwork for advanced pool management.