RFR: 8318590: JButton ignores margin when painting HTML text [v3]

[Damon Nguyen]

> The initial issue was a padding issue for JButton when HTML content was set as the button's text. [JDK-8282772](https://bugs.openjdk.org/browse/JDK-8282772), [JDK-8015854](https://bugs.openjdk.org/browse/JDK-8015854), and [JDK-8302173](https://bugs.openjdk.org/browse/JDK-8302173) are the issues related to the fix. The initial bug report was for Metal L&F, since it has a drastically different button margin from the rest (2, 14, 2, 14). This left and right margin of 14px led to the initial bug report. However, it was determined that the issue was not an issue, and instead, a problem with the reporter's implementation since they weren't aware of the difference in Metal's button margins versus other L&Fs.
> 
> This PR reverts these changes since it was determined in [this PR](https://github.com/JFormDesigner/FlatLaf/issues/746) that the fix causes a new issue regarding JButton contents' positioning.

Damon Nguyen has updated the pull request incrementally with one additional commit since the last revision:

  Remove doc change

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/16869/files
  - new: https://git.openjdk.org/jdk/pull/16869/files/b843a749..9b3e68cd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16869&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16869&range=01-02

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16869.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16869/head:pull/16869

PR: https://git.openjdk.org/jdk/pull/16869