Update Ip6Address::FromString to support address with interface

[sunytt]

Add support for address that are in the form of "fe80::1234%eth0".

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 45.92%. Comparing base (2b41187) to head (6bcc5c5).
Report is 880 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2616      +/-   ##
==========================================
- Coverage   55.77%   45.92%   -9.86%     
==========================================
  Files          87      106      +19     
  Lines        6890    12627    +5737     
  Branches        0      915     +915     
==========================================
+ Hits         3843     5799    +1956     
- Misses       3047     6511    +3464     
- Partials        0      317     +317     

☔ 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