[jfx17u] RFR: 8251483: TableCell: NPE on modifying item's list

[Jose Pereda]

Clean backport of 8251483: TableCell: NPE on modifying item's list
Reviewed-by: aghaisas, mstrauss

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Commit messages:
 - 8251483: TableCell: NPE on modifying item's list

Changes: https://git.openjdk.org/jfx17u/pull/152/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx17u&pr=152&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8251483
  Stats: 76 lines in 3 files changed: 67 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jfx17u/pull/152.diff
  Fetch: git fetch https://git.openjdk.org/jfx17u.git pull/152/head:pull/152

PR: https://git.openjdk.org/jfx17u/pull/152