Blender Git Loki

Fix for [#36599] Freestyle: Line thickness modifier with certain blend types incorrectly calculated.

The inner/outer thickness values were separately blended by Multiply, Divide and other binary
operators, which resulted in the wrong thickness values reported in the issue. The operations
must be applied to the sum of the inner and outer thickness values.

Also the Minimum and Maximum operators were not properly implemented (one of the two operands
were ignored by mistake).