test(volume-rendering): fix volume rendering lighting change test failure

Fix for volume rendering test failure due to change in lighting method. Updated the baseline test
image, and also fixed a bug caused by a typo in 'vtkTrilinearOn' macro in vtkVolumeFS.glsl.

fix #2101

Author: jadh4v

Sources/Rendering/OpenGL/VolumeMapper/test/testLighting.js

@@ -101,7 +101,7 @@ test.onlyIfWebGL('Test Lighted Volume Rendering', (t) => {
           [baseline1, baseline2],
           'Rendering/OpenGL/VolumeMapper/testMultiComponentComposite',
           t,
-          1.5,
+          0.05,
           gc.releaseResources
         );
       });

Sources/Rendering/OpenGL/VolumeMapper/test/testLighting.png

@@ -27,7 +27,7 @@ varying vec3 vertexVCVSOutput;
 // always set vtkNumComponents 1,2,3,4
 //VTK::NumComponents
 
-// possibly define vtkUseTriliear
+// possibly define vtkTrilinearOn
 //VTK::TrilinearOn
 
 // possibly define vtkIndependentComponents
@@ -224,8 +224,8 @@ uniform int xreps;
 uniform int xstride;
 uniform int ystride;
 
-// if computing triliear values from multiple z slices
-#ifdef vtkTriliearOn
+// if computing trilinear values from multiple z slices
+#ifdef vtkTrilinearOn
 vec4 getTextureValue(vec3 ijk)
 {
   float zoff = 1.0/float(volumeDimensions.z);