RFR: 8322748: Caret blinking in JavaFX should only stop when caret moves

[Andy Goryachev]

Move caret animation handling due to keyboard input to the Skin, by registering a listener on the caretPosition property.  This will restart animation only when the caret position changes instead of every key press.

This also simplifies internal behaviors of TextArea, TextField, and PasswordField in light of the future InputMap RFE [JDK-8314968](https://bugs.openjdk.org/browse/JDK-8314968)

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Commit messages:
 - Merge remote-tracking branch 'origin/master' into 8322748.blink
 - 8322748: Caret blinking in JavaFX should only stop when caret moves

Changes: https://git.openjdk.org/jfx/pull/1368/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1368&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8322748
  Stats: 22 lines in 3 files changed: 4 ins; 14 del; 4 mod
  Patch: https://git.openjdk.org/jfx/pull/1368.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1368/head:pull/1368

PR: https://git.openjdk.org/jfx/pull/1368