Emissive scene visualization is not working for Enlighten

Steps for reproduction:
- Open the scene `t1`
- Ensure that backend is set to Enlighten
- Build the lighting
- Switch the scene visualization mode to Emissive
- Observe the bug

Notes:
- Emissive property of material is set to Baked
- Regression introduced in 5.6.0b6 when Progressive Lightmapper is merged in, as scene visualization are majorly refactored
- Works as expected in Progressive Lightmapper, it does not work only in Enlighten
- Screenshots are provided below