Add normalize argument to certain image metrics

[SkafteNicki]

What does this PR do?

Fixes #1244
Adds normalize argument to inception, kid, fid metric to allow passing in float images

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• Did you make sure to update the docs?
• Did you write any new necessary tests?

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[codecov]

Codecov Report

Merging #1246 (0858d54) into master (00bb1ed) will decrease coverage by 49%.
The diff coverage is 75%.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #1246     +/-   ##
========================================
- Coverage      87%     38%    -49%     
========================================
  Files         195     195             
  Lines       11348   11360     +12     
========================================
- Hits         9840    4282   -5558     
- Misses       1508    7078   +5570     

[Borda]

@justusschock ^^ pls 🐰