Make RandomAttributeFilter visible in Paraview and add a test for it.

Change-Id: I80aa6286631cb7554f97d8a5ce2d2728c848cdde
Add an extra parameter to Random Attributes filter.

Extra parameter allows for attributes constant within a block.

Change-Id: I6f2a547fe9fc9154844db5d91f8fa235ca16d540
Merge topic '14256-random-attribute-generator' into next

0245f2c Add an extra parameter to Random Attributes filter.
11b2d67 Make RandomAttributeFilter visible in Paraview and add a test for it.