[jfx18] RFR: 8271085: TabPane: Redundant API docs

[Ajit Ghaisas]

This is a Javadoc cleanup and correction fix for the TabPane as described in the JBS.

Changes done for all the Properties of the TabPane -
- Moved the property description to be over the property field.
- Removed the unnecessary docs on property setter/getter and Property method.

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Commit messages:
 - Fix Property javadocs

Changes: https://git.openjdk.java.net/jfx/pull/728/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=728&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271085
  Stats: 122 lines in 1 file changed: 17 ins; 97 del; 8 mod
  Patch: https://git.openjdk.java.net/jfx/pull/728.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/728/head:pull/728

PR: https://git.openjdk.java.net/jfx/pull/728