[jfx17] RFR: 8264736: Fix mistakes in FX API docs

[Nir Lisker]

Fixes documentation mistakes as noted in the JBS issue.

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Commit messages:
 - Additional fix in MouseEvent
 - Initial commit

Changes: https://git.openjdk.java.net/jfx/pull/601/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=601&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8264736
  Stats: 16 lines in 3 files changed: 0 ins; 0 del; 16 mod
  Patch: https://git.openjdk.java.net/jfx/pull/601.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/601/head:pull/601

PR: https://git.openjdk.java.net/jfx/pull/601