RFR: 8041488: Locale-Dependent List Patterns

[Naoto Sato]

Introducing a new formatting class for locale-dependent list patterns. The class is to provide the functionality from the Unicode Consortium's LDML specification for [list patterns](https://www.unicode.org/reports/tr35/tr35-general.html#ListPatterns). For example, given a list of String as "Monday", "Wednesday", "Friday", its `format` method would produce "Monday, Wednesday, and Friday" in US English. A CSR has also been drafted, and its draft javadoc can be viewed here: https://cr.openjdk.org/~naoto/JDK-8041488-ListPatterns-PR/api.00/java.base/java/text/ListFormat.html

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/15130/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15130&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8041488
  Stats: 679 lines in 6 files changed: 671 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/15130.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15130/head:pull/15130

PR: https://git.openjdk.org/jdk/pull/15130