Fixes the bug that rendering an outline would remove all other effects not directly under the outline, while also improving the rendering speed drastically by only initializing and clearing the rendertarget once instead of for each effect.
This refactors the SDF Effects to use a normal blend function instead of doing the blend in the effect itself, improving quality and reducing problematic sampling issues. In addition to this, the effect files have been cleaned up slightly and renamed to their proper names. Glow and Stroke are now supported, which solves both #2 and #4 in one go.
The caching optimization has also now been implemented, reducing the number of renders for this filter to 1 for each tick.
