RFR: 4466930: JTable.selectAll boundary handling

[Prasanta Sadhukhan]

JTable.selectAll doesn't do anything if there are no rows or no columns. 
But it should still select all columns if there are no rows and the other way round. 
It is seen that isColumnSelected() will return false for all columns after calling selectAll() if there happened to be no rows.

Fix is made to select all columns even if there are no rows and similarly for rows if there are no columns.

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Commit messages:
 - 4466930: JTable.selectAll boundary handling

Changes: https://git.openjdk.org/jdk/pull/24025/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24025&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-4466930
  Stats: 103 lines in 2 files changed: 98 ins; 4 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/24025.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24025/head:pull/24025

PR: https://git.openjdk.org/jdk/pull/24025