<Swing Dev> [jdk16] RFR: 8258373: Update the text handling in the JPasswordField

[Sergey Bylokhov]

- The JTextComponent.setText() is overidden in the JPasswordField to make the "text" property non-"bound" in the JPasswordField, same as in the JTextComponent
 - The new implementation of setText() clean an internal data storage
 - Also some internal caches are cleaned as well

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Commit messages:
 - Initial fix

Changes: https://git.openjdk.java.net/jdk16/pull/39/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk16&pr=39&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8258373
  Stats: 393 lines in 7 files changed: 392 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk16/pull/39.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk16 pull/39/head:pull/39

PR: https://git.openjdk.java.net/jdk16/pull/39