Fixes LoaderInput class, email validation errors are visible now

Created by: artemruts

Description

Fixes missing classNames call that wasn't setting derived <input/> class.
That resulted in validation messages with display: none.

Created by: codecov[bot]

Codecov Report

Merging #17145 (c71d64e) into main (763864f) will decrease coverage by 0.00%. The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #17145      +/-   ##
==========================================
- Coverage   52.17%   52.17%   -0.01%     
==========================================
  Files        1710     1710              
  Lines       84450    84450              
  Branches     7817     7711     -106     
==========================================
- Hits        44062    44058       -4     
- Misses      36487    36492       +5     
+ Partials     3901     3900       -1     

Flag	Coverage Δ
go	51.31% <ø> (-0.01%)
integration	29.86% <ø> (ø)
storybook	28.94% <ø> (ø)
typescript	54.19% <ø> (ø)
unit	35.05% <ø> (ø)

Impacted Files	Coverage Δ
.../web/src/user/settings/emails/AddUserEmailForm.tsx	0.00% <ø> (ø)
.../internal/codeintel/resolvers/graphql/locations.go	83.50% <0.00%> (-2.07%)
...nal/campaigns/resolvers/changeset_apply_preview.go	58.97% <0.00%> (-1.71%)