* Add several overloads that take ReadOnlySpan<byte>
* Update to System.Memory 4.5.3
* Made a few tweaks to the text blob
- copy using new Span<T> CopyTo method
- split runbuffers out into their own file
* Add Span<T> overloads for the blob allocations
- no "clever" mapping from types, just cast
- removing variables, just use a direct call
- sk_imageinfo_t still requires mapping because of the sk_sp<T> must be mapped to a T*
- sksurfaceprops_t is now a class
Matthew Leibowitz
Nikita Tsukanov