refactor: use form for search_submission

[jennifer-richards]

Fixes 500 error when the name input contains a nul character

[codecov]

Codecov Report

Attention: Patch coverage is 95.65217% with 1 line in your changes missing coverage. Please review.

Project coverage is 88.89%. Comparing base (c7f6bde) to head (5ea1b6f).
Report is 125 commits behind head on main.

Files with missing lines	Patch %	Lines
ietf/submit/views.py	94.44%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8065      +/-   ##
==========================================
+ Coverage   88.78%   88.89%   +0.11%     
==========================================
  Files         296      304       +8     
  Lines       41320    41351      +31     
==========================================
+ Hits        36687    36761      +74     
+ Misses       4633     4590      -43     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.