fix: applying multiple filters on iOS

[jakex7]

Summary

Applying multiple FeColorFilter instances can cause unexpected behavior on iOS, likely due to a bug in CoreImage where the CIImage recipe isn't applied step by step as it should be. This fix ensures that the filter result is rendered after each application by converting the image to CGImage and then back to CIImage.

Test Plan

With this simple test, we can prove that these changes are working

<Svg height="200" width="200">
  <Filter id="filter">
    <FeColorMatrix type="matrix" values="78 -70 -7 0 0 -21 29 -7 0 0 -21 -70 0 0 0 0 0 0 1 0"/>
    <FeColorMatrix type="matrix" values="0.2126, 0.7152, 0.0722, 0, 0, 0.2126, 0.7152, 0.0722, 0, 0, 0.2126, 0.7152, 0, 0, 0, 0, 0, 0, 1, 0"/>
  </Filter>
  <Rect width="200" height="200" fill="red" filter="url(#filter)"/>
</Svg>

Web	iOS before changes	iOS after changes