Add option for extended summary in MeanAveragePrecision

[SkafteNicki]

What does this PR do?

Fixes #1938
These stats are already computed, so this is just giving the user the possibility to get them.

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

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📚 Documentation preview 📚: https://torchmetrics--1983.org.readthedocs.build/en/1983/

[codecov]

Codecov Report

Merging #1983 (b73cc01) into master (c6156b0) will decrease coverage by 48%.
The diff coverage is 95%.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #1983     +/-   ##
========================================
- Coverage      86%     39%    -48%     
========================================
  Files         266     266             
  Lines       15198   15205      +7     
========================================
- Hits        13142    5865   -7277     
- Misses       2056    9340   +7284