DrawNode: thickness is not always correct drawing e.g drawLine(...,1.9f)

[aismann]

DrawNode: thickness is not always correct e.g drawLine(...1.9f)

see
Removed hardcoded thickness clamp in DrawNode #3068

[x] remove all "hardcoded" clamps
[ ] improve/add tests on cpp-tests
[x] check/fix thickness=>1.0,<2.0 issue
[ ] thickness behavior should be the same on all drawing primitives

@w1257 as optional reviewer

[aismann]

Works for drawLine now: (thickness 1.3f)
transform = false

transform = true (thickness 1.2f)