VisRTX 0.1.5 / Tiling unit test / Misc. fixes
- Use image start/end in VisRTX backend (Requires VisRTX 0.1.5)
- Unit test for large res rendering + stitching (for both OSPRay and VisRTX)
- Disable VisRTX tone mapper to make look more similar to OSPRay
- Updated baselines
- VS 2019 include fix
Supersedes !5397 (closed)
backport: paraview/release