<i18n dev> RFR: 8333755: NumberFormat integer only parsing breaks when format has suffix

[Justin Lu]

Please review this PR and [CSR](https://bugs.openjdk.org/browse/JDK-8333920) which corrects a bug where NumberFormat cannot successfully parse values in integer only mode, when the format expects a suffix.

For example,

// a format that expects a currency suffix
var fmt = NumberFormat.getCurrencyInstance(Locale.FRANCE);
fmt.setParseIntegerOnly(true);
failFmt.parse("5,00 €"); // throws ParseException when you would have expected 5 returned


When parsing in integer only mode, instead of breaking upon a decimal symbol encounter, we should store the index but continue to fully parse so that we can verify the entire string and increment our position to search for and match the suffix. Upon a successful suffix match, we can then set `ParsePosition.index` back to the stored decimal index.

It should be noted that CompactNumberFormat did previously have code that would traverse the rest of the String, to allow matching of the suffix. The difference is that NumberFormat returns the index upon decimal symbol encounter, while CompactNumberFormat was implemented to return the index reflected by the entire string traversal. Such differences cannot be standardized due to behavioral compatibility concerns.

Thus while parsing in integer only, CNF sets index to the `Position.fullPos()`, while DF sets index to the `Position.intPos()`.

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Commit messages:
 - init

Changes: https://git.openjdk.org/jdk/pull/19664/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19664&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333755
  Stats: 180 lines in 5 files changed: 85 ins; 31 del; 64 mod
  Patch: https://git.openjdk.org/jdk/pull/19664.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19664/head:pull/19664

PR: https://git.openjdk.org/jdk/pull/19664