prigentroughnessmapalgo is hardcoded to bilinear add it to the namelist so it can change (change name to snake-case)

[ekluzek]

In ctsm5.2.019 (#1897), the item prigentroughnessmapalgo is hardcoded to bilinear, and can't be changed because it's not added to the perl build-namelist handling. It needs to be added in so it can be changed, which is helpful for testing, and may be helpful for users to have control how the dataset is interpolated.

Definition of done:

• Change the name to prigent_roughness_mapalgo for consistency with other Prigent stream namelist control
• Add to the namelist_definiton file
• Add to the perl build-namelist code
• Add some tests for it to the build-namelist unit tester
• Add testing to make sure it can change