CLI option to select allocation strategy

[giann]

Depending on what type of program you might be writting with buzz. You might want to fine-tune the allocation strategy used:

• Small memory footprint and short lifespan: arena allocator
• Long lived loop with many short-lived objects (game): something like https://nullprogram.com/blog/2023/09/27/
• Others ?
• Default: mimalloc

This is only useful if performance impact is significant compared to mimalloc in those specific contexts.