fix: add default value support for controlled textfield components

[scottyoung]

Description of changes:
This is a follow up to moving TextField to a controlled component. Since it's controlled, we can no longer use the defaultValue param, we have to pass in the default value to the initialValue object.

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[codecov-commenter]

Codecov Report

Merging #884 (7375509) into main (7c5ab39) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #884      +/-   ##
==========================================
+ Coverage   92.94%   92.96%   +0.01%     
==========================================
  Files         117      117              
  Lines        4961     4974      +13     
  Branches     1441     1446       +5     
==========================================
+ Hits         4611     4624      +13     
  Misses        329      329              
  Partials       21       21              

Impacted Files	Coverage Δ
...lib/generate-form-definition/helpers/form-field.ts	98.92% <ø> (ø)
...react/lib/forms/form-renderer-helper/form-state.ts	98.83% <100.00%> (+0.04%)	⬆️
.../codegen-ui-react/lib/forms/react-form-renderer.ts	95.81% <100.00%> (ø)
packages/codegen-ui-react/lib/helpers/index.ts	100.00% <100.00%> (ø)

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