RFR: 8315655: [macos] Right click and dragging over a component with a popup menu will open the popup [v2]

[Alisen Chung]

> Issue is a mouse drag will trigger a popup in macos, but not in linux or windows.
> The solution is to add a check for a mouse pressed event to show popup and prevent mouse entered events from triggering the popup

Alisen Chung has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - Merge branch 'master' of github.com:openjdk/jdk into 8315655
 - fix trailing whitespace in instructions string
 - fix line ender
 - fix whitespaces and newline
 - fix whitespaces and newline
 - init commit

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Changes:
  - all: https://git.openjdk.org/jdk/pull/19569/files
  - new: https://git.openjdk.org/jdk/pull/19569/files/d8758e03..bf890aa9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19569&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19569&range=00-01

  Stats: 589 lines in 11 files changed: 487 ins; 2 del; 100 mod
  Patch: https://git.openjdk.org/jdk/pull/19569.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19569/head:pull/19569

PR: https://git.openjdk.org/jdk/pull/19569