Nested Exif Metadata support + Gate fixes for py 3.7 and keras version

[Advitya17]

Adds nested metadata support, simultaneous ask from 2 customers. Also fixed gates by removing py 3.7 and pegging keras version as 3.0 may not support transformers due to breaking changes, resulting in the need of pegging keras to version 2 and having backwards-compatible tensorflow/keras.

Description

Checklist

• I have added screenshots above for all UI changes.
• I have added e2e tests for all UI changes.
• Documentation was updated if it was needed.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.12%. Comparing base (e2c7dd0) to head (5f2fe62).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2545      +/-   ##
==========================================
- Coverage   84.00%   78.12%   -5.89%     
==========================================
  Files          95       36      -59     
  Lines        4958     2619    -2339     
==========================================
- Hits         4165     2046    -2119     
+ Misses        793      573     -220     

Flag	Coverage Δ
unittests	78.12% <ø> (-5.89%)	⬇️

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