Add fit tests for tabular tasks

[ethanwharris]

What does this PR do?

Part of #1183

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• Did you write any new necessary tests? [not needed for typos/docs]
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[codecov]

Codecov Report

Merging #1332 (e379bef) into master (07d63e3) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1332      +/-   ##
==========================================
- Coverage   91.47%   91.46%   -0.02%     
==========================================
  Files         287      287              
  Lines       12881    12894      +13     
==========================================
+ Hits        11783    11793      +10     
- Misses       1098     1101       +3     

Flag	Coverage Δ
unittests	91.46% <100.00%> (-0.02%)	⬇️

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

Impacted Files	Coverage Δ
flash/core/integrations/pytorch_tabular/adapter.py	96.96% <100.00%> (+0.19%)	⬆️
.../image/classification/integrations/baal/dropout.py	92.30% <0.00%> (-2.94%)	⬇️
...ash/image/classification/integrations/baal/data.py	87.85% <0.00%> (-0.94%)	⬇️
flash/core/utilities/imports.py	91.42% <0.00%> (-0.29%)	⬇️
...ash/image/classification/integrations/baal/loop.py	94.92% <0.00%> (ø)

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