Add Boundary::toHeader() to simplify building requests

[Baptouuuu]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.14%. Comparing base (ea5d53e) to head (0787ebf).
Report is 2 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop      #18   +/-   ##
==========================================
  Coverage      96.13%   96.14%           
- Complexity      1095     1096    +1     
==========================================
  Files            197      197           
  Lines           4711     4721   +10     
==========================================
+ Hits            4529     4539   +10     
  Misses           182      182           

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.