RFR: 8181084: JavaFX show big icons in system menu on macOS with Retina display

[Paul]

I hit on JDK-8181084 while making some changes to Scene Builder, so I decided 
to investigate.

Please note: I have not done any Objective-C or MacOS development before. So I 
would really like some feedback from someone else who knows this stuff better.

Anyway, after some googling, I discovered that MacOS uses points values for 
measurements and not pixels, so the actual fix for this issue was this block in 
`GlassMenu.m`:-


            if ((sx > 1) && (sy > 1) && (width > 1) && (height > 1)) {
                NSSize imgSize = {width / sx, height / sy};
                [image setSize: imgSize];
            }


The rest of the changes were needed in order to get the `scaleX` and `scaleY` 
values down from `PixelUtils.java` into `GlassMenu.m`.

Before this fix:-

<img width="239" alt="Screenshot 2022-02-26 at 22 16 30" 
src="https://user-images.githubusercontent.com/437990/155880981-92163087-696b-4442-b047-845c276deb27.png";>

After this fix:-

<img width="218" alt="Screenshot 2022-02-26 at 22 18 17" 
src="https://user-images.githubusercontent.com/437990/155880985-6bff0a06-9aee-4db2-b696-64730b0a6feb.png";>

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

Commit messages:
 - Removing trailing whitespace.
 - Correctly scales hi-res icons in MacOS system menu items

Changes: https://git.openjdk.java.net/jfx/pull/743/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=743&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8181084
  Stats: 86 lines in 14 files changed: 84 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jfx/pull/743.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/743/head:pull/743

PR: https://git.openjdk.java.net/jfx/pull/743