Implement BPF_F_NO_PREALLOC and default to pre-allocating memory for maps

https://learn.microsoft.com/en-us/windows-hardware/drivers/kernel/using-lookaside-lists

Profiling indicates that pool allocation / free represents a high percentage of our CPU time for some scenarios. It might make sense to then maintain a look aside list to speed up allocations / frees.

Start with the linked Microsoft lookaside-list guidance, then locate the map allocation and free paths in the repository; the issue names no files or tests. Done means implementing BPF_F_NO_PREALLOC and default map pre-allocation, with the reported pool allocation and free overhead addressed.

Written by the indexing model from the issue text.