Add WPT for CSP with trailing dot in hostname

This CL adds a generic WPT test to make sure hosts with trailing dots can be defined in CSP. The CL targets connect-src directive as a proof of concept. More tests can be added for other directives later on.

Bug: 1512075 Change-Id: Ia3d8ec4c4b6594d46ff6c65ff8275bfd6bdd70fb Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5185382 Reviewed-by: Antonio Sartori antoniosartori@chromium.org Commit-Queue: Saeid Eid saeideid@chromium.org Reviewed-by: Jonathan Hao phao@chromium.org Cr-Commit-Position: refs/heads/main@{#1246451}