VISSL datapipeline fix

[ananyahjha93]

What does this PR do?

Fixes datapipeline to work with VISSL's list transforms + adds process-state for PerSampleTransformOnDevice, PerBatchTransform, PerBatchTransformOnDevice. Adds option to set these to None and override the defaults provided.

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[codecov]

Codecov Report

Merging #880 (96192ba) into master (b41722a) will increase coverage by 0.01%.
The diff coverage is 91.83%.

@@            Coverage Diff             @@
##           master     #880      +/-   ##
==========================================
+ Coverage   85.25%   85.26%   +0.01%     
==========================================
  Files         230      230              
  Lines       12666    12706      +40     
==========================================
+ Hits        10798    10834      +36     
- Misses       1868     1872       +4     

Flag	Coverage Δ
unittests	85.26% <91.83%> (+0.01%)	⬆️

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

Impacted Files	Coverage Δ
flash/image/embedding/model.py	89.83% <83.33%> (-0.92%)	⬇️
flash/core/data/process.py	87.77% <91.17%> (+0.07%)	⬆️
flash/core/data/states.py	100.00% <100.00%> (ø)

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