Expose NumberFormatter and NumberRangeFormatter APIs

Formatter APIs:
android.icu.number.NumberFormatter
android.icu.number.NumberFormatterSettings
android.icu.number.LocalizedNumberFormatter
android.icu.number.LocalizedNumberRangeFormatter
android.icu.number.NumberRangeFormatter
android.icu.number.NumberRangeFormatterSettings
android.icu.number.UnlocalizedNumberFormatter
android.icu.number.UnlocalizedNumberRangeFormatter

The formatted values are stored in:
android.icu.number.FormattedNumber
android.icu.number.FormattedNumberRange

The rest of API classes/enums are added for the macro settings of number format.

Note that skeleton APIs are hidden right now due to its evolvement of
syntax.

Bug: 134040863
Test: m droid
Change-Id: Ib07c8115d54bfcaac9d045f616dae6f3f546df93