APIs missing: set Fills blending options
Similarly to the Opacity, this option is not currently available in the APIs:
<img width="309" alt="CleanShot 2022-06-23 at 11 50 25" src="https://user-images.githubusercontent.com/72731885/175282413-6ed3dae8-1d3e-47a3-aaf4-e78d26e2e004.png">

Currently, it is possible to set them only via:
`layer.style.sketchObject.fills()[1].contextSettings().setBlendMode(13);`

It would be nice to have something like:
`layer.style.fills[value].blendMode = "Overlay"`

It is also missing a way to read the option:
`layer.style.sketchObject.fills()[1].contextSettings().blendMode();`
