RFR: 8341975: Unable to set encoding for IO.println, IO.print and IO.readln

[Naoto Sato]

Changing the charset initialization of `java.io.Console` class, which is the basis of `java.io.IO`, so that it would behave the same way as `System.out` wrt encoding. This change will also have the capability to override the default charset used in `IO` methods with `stdout.encoding` system property. A corresponding CSR has also been drafted.

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Commit messages:
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/21569/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21569&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8341975
  Stats: 93 lines in 4 files changed: 52 ins; 37 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/21569.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21569/head:pull/21569

PR: https://git.openjdk.org/jdk/pull/21569