MacOS Liquid Glass Icons for the Eclipse Packages

[BeckerWdf]

Apple has introduced Liquid Glass icons. See: https://developer.apple.com/design/human-interface-guidelines/app-icons

Similar to eclipse-platform/eclipse.platform.ui#1247 we should follow this an provide a liquid glass version for our package.

[BeckerWdf]

We already did this for SAP ABAP Development Tools. So I and @sratz know what needs to be done. I can provide a PR for this.

[merks]

EPP generally syncs with what the platform is doing.

packages/RELEASING.md

Lines 51 to 53 in d59bd0e

	- [ ] Synchronize any changes to [platform's icons](
	https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/tree/master/eclipse.platform.releng.tychoeclipsebuilder/eclipse.platform.repository/icons
	) into `icons` root directory.

But it looks like that link to what we need to sync with is broken now. It should be this now I believe.

https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/tree/master/products/icons

It should go here:

https://github.com/eclipse-packaging/packages/tree/master/icons

I looks like the readme is updated:

https://github.com/eclipse-packaging/packages/blob/master/icons/README.md

But I guess this is still old?

https://github.com/eclipse-packaging/packages/blob/master/icons/Eclipse.icns

[merks]

I'm confused by the stated goal here. This commit copied the Eclipse.icns from the Platform to EPP:

b81ff4b

Currently what the Platform has for icons and what EPP has for icons are identical.

So if something need to change, it should be changed in the Platform and then EPP will sync with that following the usual steps.