Add missing pooling allocator options as CLI flags (#9256)

[omarjatoi]

From #9256, this PR adds the missing pooling allocator configuration options as CLI flags. I also renamed some minor things for consistency.

• Adds missing PoolingAllocatorConfiguration to the OptimizeOptions struct
• Set configuration when pooling-allocator is enabled and flags are passed
• Fixes pooling_decommit_batch_size type to usize
• Rename memory_protection_keys to pooling_memory_protection_keys

[fitzgen]

Thanks! Just a couple comments below

[omarjatoi]

Thanks for the comments! I've added defaults in comments and cleaned up the commits.

[fitzgen]

Thanks!