refactor(vm): Eliminate code duplication in UnifiedMemory using macro

[letmehateu]

Describe your changes.

Introduces a declarative macro to eliminate ~120 lines of duplicated code in vm/src/memory/unified.rs. Three nearly identical methods (addr_val_bytes, segment_words, segment_bytes) are now generated using the dispatch_method! macro.

Three methods contained almost identical dispatch logic:

• addr_val_bytes() - ~40 lines
• segment_words() - ~40 lines
• segment_bytes() - ~40 lines

The only differences were:

• Method name being called on the underlying store
• Parameters passed to the method
• Return type

This duplication made the code harder to maintain - any change to the dispatch logic required updating all three methods identically.

[sjudson]

I think I'm going to pass on this, the macro is a bit too clunky to be worth the DRY savings. Clarity is more important.