* refactor: replace usage of ByteMemoryPool with MemoryOwner<byte>
* refactor: delete unused ByteMemoryPool and ByteMemoryPool.ByteMemoryPoolBuffer types
* refactor: change IMemoryOwner<byte> return types to MemoryOwner<byte>
* fix(perf): get span via `MemoryOwner<T>.Span` directly instead of `MemoryOwner<T>.Memory.Span`
* fix(perf): get span via MemoryOwner<T>.Span directly instead of `MemoryOwner<T>.Memory.Span`
* fix(perf): get span via MemoryOwner<T>.Span directly instead of `MemoryOwner<T>.Memory.Span`
* - add new abstract class `VirtualMemoryManagerBase`
- rename `MemoryManagerBase` to `VirtualMemoryManagerRefCountedBase` and derive from `VirtualMemoryManagerBase`
- change `AddressSpaceManager`, `HvMemoryManager`, `MemoryManager`, and `MemoryManagerHostMapped` to implement abstract members and use the inherited `void VirtualMemoryManagerBase.Read(TVirtual va, Span<byte> data)` implementation.
* move property `AddressSpaceSize` up by the other properties