cudf::rolling_window SUM support for decimal32 and decimal64

[codereport]

This PR resolves #7117 by adding support for cudf::rolling for the SUM option for decimal32 and decimal64.

[davidwendt]

Is there an invalid fixed-point/aggregation-type you want to test with EXPECT_THROW?

[codecov]

Codecov Report

Merging #7147 (11be93f) into branch-0.18 (8860baf) will decrease coverage by 0.00%.
The diff coverage is 84.00%.

@@               Coverage Diff               @@
##           branch-0.18    #7147      +/-   ##
===============================================
- Coverage        82.09%   82.09%   -0.01%     
===============================================
  Files               97       97              
  Lines            16474    16516      +42     
===============================================
+ Hits             13524    13558      +34     
- Misses            2950     2958       +8     

Impacted Files	Coverage Δ
python/cudf/cudf/core/column/lists.py	91.66% <ø> (-0.09%)	⬇️
python/cudf/cudf/core/series.py	91.08% <66.66%> (-0.07%)	⬇️
python/cudf/cudf/core/column/numerical.py	94.17% <80.00%> (-0.24%)	⬇️
python/cudf/cudf/core/reshape.py	91.00% <81.81%> (-0.04%)	⬇️
python/cudf/cudf/core/dtypes.py	89.50% <100.00%> (-0.88%)	⬇️
python/cudf/cudf/io/csv.py	90.74% <100.00%> (-2.60%)	⬇️
python/cudf/cudf/io/orc.py	86.39% <0.00%> (-2.02%)	⬇️
python/cudf/cudf/_fuzz_testing/fuzzer.py	0.00% <0.00%> (ø)
... and 4 more

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