RFR: 8358468: Enhance code consistency: java.desktop/macos [v3]

[Sergey Bylokhov]

> This PR updates the last (!!) remaining platform-specific part of the java.desktop module: macos.
> The unix/windows were previously addressed in: https://github.com/openjdk/jdk/pull/24170 , https://github.com/openjdk/jdk/pull/24941 and https://github.com/openjdk/jdk/pull/25439.
> 
> Note: Unlike on other platforms, the initial change for macOS caused the "BadSerializationTest" to fail. This test relies on internal details of the Aqua Look & Feel that were previously exposed via serialized data (and already [fails](https://bugs.openjdk.org/browse/JDK-8277817) on other platforms). Adding the final modifier to the class changes its serialVersionUID, which triggered the failure even on macOS.
> To avoid this issue, I have reverted the changes to those internal classes for now, see https://github.com/openjdk/jdk/pull/25607/commits/ff7e64b6e38a1a809d434628f304e49408135697
> 
> To download the diff file and filter only the modified lines you can use the following script:
> 
> 
> curl -s https://patch-diff.githubusercontent.com/raw/openjdk/jdk/pull/25607.diff -o d.txt && grep -E '^+|^-' d.txt | grep -vE '^+++|^---'
> 
> ====================================================
> 
> The `java.desktop` module currently lacks proper use of the `@Override` annotation for methods and the `final` modifier for classes. While similar changes were previously made in the [JavaSound](https://github.com/openjdk/jdk/commit/e0c7d59246cf36644d494eced76e4b9d96ff1ded#diff-ae3e5f9c40fe25ef03e7a89844de174ef5c15e6179d769e2a4bcb7e73688c9b5), [java.desktop/windows](https://github.com/openjdk/jdk/pull/24170) (and some of the classes on demand), these changes are not as critical now due to the new jdk "encapsulation", but they are still useful for improving code consistency.
> 
> The public API was not affected so there is no need to worry about a CSR
> 
> Note: I will submit additional patches in this area later because:
> 
> 1. Only lines with `@Override` and `final` were modified to keep the diff clear - header dates were not updated (that could be covered by one patch similar to [this](https://bugs.openjdk.org/browse/JDK-8345797))
> 2. I skipped adding `@Override` for anonymous classes
> 
> Any feedback or suggestions are welcome!
> 
> Here is a [link](https://patch-diff.githubusercontent.com/raw/openjdk/jdk/pull/25607.diff) to a simple diff file, it might be more convenient for reviewing the changes.
> 
> The build was successful, and I ran all the open jtreg tests without issues. But it's possible that some closed tests may be affected ...

Sergey Bylokhov 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 'openjdk:master' into over_macos
 - Merge branch 'openjdk:master' into over_macos
 - Fix java/awt/dnd/BadSerializationTest/BadSerializationTest.java test
 - restore formatting
 - final in java.desktop/macos
 - override in java.desktop/macos

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25607/files
  - new: https://git.openjdk.org/jdk/pull/25607/files/2ebaf02d..dca9c7ab

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25607&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25607&range=01-02

  Stats: 4677 lines in 139 files changed: 1254 ins; 3071 del; 352 mod
  Patch: https://git.openjdk.org/jdk/pull/25607.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25607/head:pull/25607

PR: https://git.openjdk.org/jdk/pull/25607