Add support for IDNA 2008 (RFC 5891) when encoding URL (#819)

[j-bernard]

Description

Convert URL host to A-Label before making a request. IDNA object is provided by ICU4j dependency for JVM but on Android it is included in android.icu.text.IDNA so you may want to handle it differently for Android which I did not do.

Fixes #819

Type of change

• [x] Bug fix (a non-breaking change which fixes an issue)
• [ ] New feature (a non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Refactoring (a change which changes the current internal or external interface)
• [ ] This change requires a documentation update

Checklist:

• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation, if necessary
• [ ] My changes generate no new compiler warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Inspect the bytecode viewer, including reasoning why

[kittinunf]

Thanks for the PR, let me try to find out what's wrong with the travis CI, maybe we probably need to move over to Github action instead.

[arnt]

Hi,

why was this closed? It looks quite nifty.

[arnt]

Oh, it's not necessary. Fuel uses OkHttp, which added IDNA2008 support a month or two ago. Fuel should then not need anything itself, AIUI. Agree?