RFR: 8298971: Move Console implementation into jdk internal package [v2]

[Naoto Sato]

> Moving the built-in implementation of `Console` from `java.io` package into `jdk.internal.io` package. It now implements `JdkConsole` interface and is accessed through `ProxyingConsole`.

Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:

  Removed JdkConsoleProviderImpl, caching INSTANCE

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Changes:
  - all: https://git.openjdk.org/jdk/pull/11729/files
  - new: https://git.openjdk.org/jdk/pull/11729/files/665b626d..777c0dc0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11729&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11729&range=00-01

  Stats: 55 lines in 2 files changed: 8 ins; 18 del; 29 mod
  Patch: https://git.openjdk.org/jdk/pull/11729.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11729/head:pull/11729

PR: https://git.openjdk.org/jdk/pull/11729