Bug 28124: Show Tor Browser icon as macOS volume (dmg) icon

Merge Info

• Related Issues

  • #28124 (closed)

• Backport Timeline

  • Immediate - patchsets for critical bug fixes or other major blocker (e.g. fixes for a 0-day exploit) OR patchsets with trivial changes which do not need testing (e.g. fixes for typos or fixes easily verified in a local developer build)
  • Next Minor Stable Release - patchset that needs to be verified in nightly before backport
  • Eventually - patchset that needs to be verified in alpha before backport
  • No Backport - patchset for the next major stable

• Issue Tracking

  • Link resolved issues with appropriate Release Prep issue for changelog generation

Change Description

This MR enables the custom icon on dmg files.

To do so, I had to switch to HFS for the image file, so the MR is divided in three parts:

1. switch to Mozilla's fork of libdmg-hfsplus, copy also the hfsplus utility in addition to dmg, and add the hfsplus-tools project
2. use the new projects to build a DMG with HFS
3. update the old icon with the new one from tor-browser#41332 (closed).

Closes #28124 (closed)