file_util: Early-exit in WriteArray and ReadArray if specified lengths are zero

Implement a new virtual memory manager

gl_query_cache: Resolve use-after-move in CachedQuery move assignment operator

- Should be no functional changes.

- Includes removing some service impls. that are untested.

- Includes removing some SVC impls. that are untested.

- Fixes Super Smash Bros. Ultimate.

- More consistent with other system components.