FI-2040: Fix JSON parse error for OAuth inputs

[AlyssaWang]

Summary

JSON string parsing and type handling was throwing errors in the input fields for OAuth, particularly when switching between field inputs to serial inputs. This should no longer occur.

Testing Guidance

1. Before, editing JSON inputs where an OAuth input was present would cause snackbar errors to appear indicating the JSON could not be parsed. This should be fixed.

2. Before, editing the OAuth fields in the JSON input and then switching back to field inputs would throw an uncaught JSON parse error. This should be fixed. Making changes and switching between inputs should be error free.

These can be tested in the Demonstration Suite.

[codecov]

Codecov Report

Patch coverage: 35.61% and project coverage change: -0.10% ⚠️

Comparison is base (990a1ab) 77.17% compared to head (3c34375) 77.08%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #377      +/-   ##
==========================================
- Coverage   77.17%   77.08%   -0.10%     
==========================================
  Files         211      211              
  Lines       10362    10382      +20     
  Branches      960      960              
==========================================
+ Hits         7997     8003       +6     
- Misses       1807     1821      +14     
  Partials      558      558              

Flag	Coverage Δ
backend	94.51% <ø> (ø)
frontend	69.61% <35.61%> (-0.11%)	⬇️

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

Files Changed	Coverage Δ
...c/components/InputsModal/InputOAuthCredentials.tsx	22.91% <0.00%> (-0.66%)	⬇️
client/src/components/InputsModal/InputsModal.tsx	55.89% <35.84%> (-1.58%)	⬇️
client/src/components/Footer/Footer.tsx	66.12% <100.00%> (+1.14%)	⬆️

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