RFR: 8349664: HEX dump should always use ASCII or ISO_8859_1 [v2]

[Mikhail Yankelevich]

> Changed `HexDumpEncoder`, so `encodeBuffer` always uses ISO_8859_1. 
> This also fixes the issue with conversion in `encode` method, as the input is always ISO_8859_1.

Mikhail Yankelevich has updated the pull request incrementally with one additional commit since the last revision:

  tests added

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/23661/files
  - new: https://git.openjdk.org/jdk/pull/23661/files/a83f2433..a9244ed8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23661&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23661&range=00-01

  Stats: 124 lines in 1 file changed: 124 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/23661.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23661/head:pull/23661

PR: https://git.openjdk.org/jdk/pull/23661