Bugfix for using metric collection and aggregation metric

[SkafteNicki]

What does this PR do?

Fixes #1890

Essentially, if a user provides a single value like torch(1.0) then the state of SumMetric, MeanMetric, MinMetric, MaxMetricis the exact same after the firstmetric.update` call (sum(1) == mean(1) == max(1) == min(1)). In this case metric collection interprets that these should be in the same compute group, which is wrong.
Fixes this by given unique state names

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📚 Documentation preview 📚: https://torchmetrics--1896.org.readthedocs.build/en/1896/

[codecov]

Codecov Report

Merging #1896 (acb0e35) into master (e1fd252) will increase coverage by 0%.
The diff coverage is 100%.

Additional details and impacted files

@@          Coverage Diff           @@
##           master   #1896   +/-   ##
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  Coverage      85%     85%           
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  Files         262     262           
  Lines       15049   15052    +3     
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+ Hits        12798   12801    +3     
  Misses       2251    2251