GPU-based IW-SSIM processing

[denproc]

Closes #310

Proposed Changes

• Add torch version handler
• Eliminate torch==1.8.* and torchvision==0.9.* from requirements
• In case of torch==1.9.* and torchvision==0.10.* use torch.symeig instead of torch.linalg.eigh
• Tested on GPU

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[codecov]

Codecov Report

Merging #311 (b196b8b) into master (9da71aa) will increase coverage by 2.25%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #311      +/-   ##
==========================================
+ Coverage   91.87%   94.12%   +2.25%     
==========================================
  Files          34       34              
  Lines        2486     2486              
==========================================
+ Hits         2284     2340      +56     
+ Misses        202      146      -56     

Flag	Coverage Δ
unittests	94.12% <100.00%> (+2.25%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
piq/iw_ssim.py	100.00% <100.00%> (ø)
piq/feature_extractors/fid_inception.py	99.23% <0.00%> (+1.53%)	⬆️
piq/gs.py	92.30% <0.00%> (+59.34%)	⬆️

[jzakirov]

LGTM 👍🏼