Support Intl bestFit matching

[TatianaKapos]

Problem

Currently the Windows implementation of DateTimeFormat::supportedLocalesOf does not support bestFit matching. Android supports this feature while apple does not (yet).

ICU uses localematcher in C++ but does not have an equivalent in C. We should figure out a way around this to add support for bestFit. This will affect supportedLocalesOf NumberFormat and Collator

https://402.ecma-international.org/9.0/#sec-bestfitmatcher