RFR: 8354724: BufferedReader readAllLines and readString methods [v5]

[Brian Burkhalter]

> Implement the requested methods and add a test thereof.

Brian Burkhalter has updated the pull request incrementally with two additional commits since the last revision:

 - 8354724: Increment copyright year in Reader
 - 8354724: Move readString from BufferedReader to Reader

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Changes:
  - all: https://git.openjdk.org/jdk/pull/24728/files
  - new: https://git.openjdk.org/jdk/pull/24728/files/422703fe..8b0b9238

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24728&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24728&range=03-04

  Stats: 72 lines in 2 files changed: 35 ins; 36 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/24728.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24728/head:pull/24728

PR: https://git.openjdk.org/jdk/pull/24728