Add post effects filters to eeve render

it would nice to add realtime post effects filters to eeve renderer, effects like

1. bleach bypass
2. noise
3. chromatic abberation
4. heat distrotion
5. flash
6. desaturation
7. exposure
8. scanline
9. tritone
10. quad tone
11. matcap filter
12. lens distortion and warping
13. day for night
14. curves
15. color grade
16. brightness and contrast
17. invert
18. wave

the filters can be recalled multiple time and be stacked in a layered fashion. those layers can deleted dynamically.

thanks.

Agapi simon.