[NPU] Make zero mem pool global per core and not per process (#35121)
### Details:
- *Make the zero mem pool global per core and not per process*
### Tickets:
- *N/A*
### AI Assistance:
- *AI assistance used: no / yes*
- *If yes, summarize how AI was used and what human validation was
performed (build/tests/manual checks).*
---------
Signed-off-by: Bogdan Pereanu <bogdan.pereanu@intel.com>