Bug/4823 upload file with leading space

[robinmolen]

Closes #4823

Changes

When uploading a file with a leading space, the website will show a descriptive error message.

Checklist

Check off the items that are completed or not relevant.

• Impact on features

  • Checked copying a form
  • Checked import/export of a form
  • Config checks in the configuration overview admin page
  • Problem detection in the admin email digest is handled

• Release management

  • I have labelled the PR as "needs-backport" accordingly

• I have updated the translations assets (you do NOT need to provide translations)

  • Ran ./bin/makemessages_js.sh
  • Ran ./bin/compilemessages_js.sh

• Commit hygiene

  • Commit messages refer to the relevant Github issue
  • Commit messages explain the "why" of change, not the how

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 96.56%. Comparing base (4b73a1d) to head (d50482a).
Report is 15 commits behind head on master.

Files with missing lines	Patch %	Lines
src/openforms/formio/components/vanilla.py	0.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4830      +/-   ##
==========================================
- Coverage   96.57%   96.56%   -0.01%     
==========================================
  Files         747      747              
  Lines       25400    25402       +2     
  Branches     3355     3356       +1     
==========================================
  Hits        24529    24529              
- Misses        608      609       +1     
- Partials      263      264       +1     

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

---

🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests
• JS Bundle Analysis - Avoid shipping oversized bundles

[robinmolen]

Closed this PR in favor of #4833