RFR: 8351878: RichTextArea: Pasting from RTF doesn't apply formatting

[Andy Goryachev]

Fixed two issues found in importing RTF text:

- Arabic import
- missing font size

The former was caused by my removal of the character decoder code present in the original JDK RTF parser/reader.  Why did I do that?

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Commit messages:
 - font size
 - fixed arabic import

Changes: https://git.openjdk.org/jfx/pull/1735/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1735&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351878
  Stats: 157 lines in 3 files changed: 150 ins; 1 del; 6 mod
  Patch: https://git.openjdk.org/jfx/pull/1735.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1735/head:pull/1735

PR: https://git.openjdk.org/jfx/pull/1735