Refactor Analyzers: Unify Range Logic & Optimize Allocations (#1464)

* refactor

* optimizations

* Refactor analyzers: unify range logic and optimize allocations- Centralize numeric range analysis in util.go (shared by G115/G602).- Implement object pooling for slice_bounds and hardcoded_nonce.- Update conversion_overflow tests to use real analyzer logic.

* Refactor RangeAnalyzer

Author: oittaa