RFR: 8274148: can jshell show deprecated classes, methods and fields as strikethrough text?

[Jan Lahoda]

This adds a limited highlighting for JShell. It underlines keywords, highlights declarations and shows deprecated elements inversed (on platforms other than Linux) or with a strikethrough (on Linux).

For example, non-Linux platforms:
![jshell-coloring-other](https://user-images.githubusercontent.com/51319204/149968951-df00b3a0-0463-4a9a-9d48-49925030409e.png)

Linux:
![jshell-coloring-linux](https://user-images.githubusercontent.com/51319204/149968969-93c75731-de41-4ac5-b5c0-a1ac2a32ddd8.png)

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Commit messages:
 - 8274148: can jshell show deprecated classes, methods and fields as strikethrough text?

Changes: https://git.openjdk.java.net/jdk/pull/7130/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7130&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274148
  Stats: 700 lines in 6 files changed: 647 ins; 47 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7130.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7130/head:pull/7130

PR: https://git.openjdk.java.net/jdk/pull/7130