[jdk19u] RFR: 8296632: Write a test to verify the content change of TextArea sends TextEvent

[Victor Rudometov]

Backport for [JDK-8296632](https://bugs.openjdk.org/browse/JDK-8296632) Write a test to verify the content change of TextArea sends TextEvent https://git.openjdk.org/jdk/commit/59a308b9d0546471566b11f62ef9bdc169ca0b95

Clean Backport.
New test, low risk.
Test passes during manual run: make run-test TEST="test/jdk/java/awt/event/ComponentEvent/TextAreaTextEventTest.java"

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Commit messages:
 - 8296632: Write a test to verify the content change of TextArea sends TextEvent

Changes: https://git.openjdk.org/jdk19u/pull/76/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19u&pr=76&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296632
  Stats: 141 lines in 1 file changed: 141 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk19u/pull/76.diff
  Fetch: git fetch https://git.openjdk.org/jdk19u pull/76/head:pull/76

PR: https://git.openjdk.org/jdk19u/pull/76