Refactor DSS to better leverage DataLayouts

Remove unused indices and methods

Fix some conversions

Author: charleskawczynski

NEWS.md

@@ -4,6 +4,8 @@ ClimaCore.jl Release Notes
 main
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+- DSS was refactored, and machine precision changes can be expected. PR [#1958](https://github.com/CliMA/ClimaCore.jl/pull/1958).
+
 v0.14.12
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 - Added hyperbolic tangent stretching. PR [#1930](https://github.com/CliMA/ClimaCore.jl/pull/1930).