Add support for CLUSTER DELSLOTSRANGE

[dvora-h]

Pull Request check-list

Please make sure to review and check all of these items:

• Does $ tox pass with this change (including linting)?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?
• Is there an example added to the examples folder (if applicable)?
• Was the change added to CHANGES file?

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Description of change

closes #1803

[codecov-commenter]

Codecov Report

Merging #2018 (5793580) into master (4a714aa) will decrease coverage by 0.48%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master    #2018      +/-   ##
==========================================
- Coverage   92.63%   92.14%   -0.49%     
==========================================
  Files         100      100              
  Lines       20909    21006      +97     
==========================================
- Hits        19369    19356      -13     
- Misses       1540     1650     +110     

Impacted Files	Coverage Δ
redis/client.py	89.39% <ø> (ø)
redis/cluster.py	91.93% <ø> (-0.58%)	⬇️
tests/test_cluster.py	98.04% <33.33%> (-0.25%)	⬇️
redis/commands/cluster.py	94.11% <100.00%> (-0.71%)	⬇️
tests/test_function.py	25.30% <0.00%> (-74.70%)	⬇️
redis/commands/timeseries/__init__.py	94.73% <0.00%> (-5.27%)	⬇️
redis/commands/json/__init__.py	97.56% <0.00%> (-2.44%)	⬇️
redis/commands/parser.py	88.40% <0.00%> (-1.92%)	⬇️
redis/commands/core.py	85.86% <0.00%> (-1.36%)	⬇️
... and 9 more

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