RFR: 8309558: Create implementation of NSAccessibilityCheckBox protocol

[Alexander Zuev]

also
8309629: Create implementation of NSAccessibilityRadioButton protocol

Create implementation of NSAccessibilityCheckBox and NSAccessibilityRadioButton protocols
Add workaround for the wrong focus owner announcement with radio buttons
Add workaround for wrong magnifier text on buttons

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Commit messages:
 - 8309558: Create implementation of NSAccessibilityCheckBox protocol

Changes: https://git.openjdk.org/jfx/pull/1184/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1184&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8309558
  Stats: 184 lines in 6 files changed: 183 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1184.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1184/head:pull/1184

PR: https://git.openjdk.org/jfx/pull/1184