Add more blending modes

Add more blending modes such as:

+ destination
+ destination-over
+ source-out and destination-out
+ source-in and destination-in
+ source-atop, destination-atop
+ xor

More information about alpha compositing can be found here:

https://ciechanow.ski/alpha-compositing/

New blending modes should be added to blend (CPU-based blending) and glblend  (GPU-based blending)
