v18.0.0-alpha

Added

• ServiceRegistry class implementing the service locator pattern.
  Integrated it with Registry.

Changed

• Empty type optimization (tags) now only applies to value types, instead of any type without fields.
• Renamed TrimmedFilter to ReducedFilted and tweak some internal method names.
• Reworked TypeIdentifier and GenericLookup.
• Optimize FilterView.ForEach() methods for cases where a minimal set is one of the selected data sets.
• Moved serialization to a separate package to eliminate unsafe code from the core library.
• PageSequence now use Page struct to iterate.
• MassiveRegistry now saves first empty for MassiveEntities on creation.

Fixed

• IL2CPP stripping for ICopyable<T>.