Review Bundle-Data and try not to ship the default profile in base browser

I think we have some room for improvement in the mechanism that copies the Bundle-Data directory.

Problems I found:

• Base Browser contains Data/Tor
  • Solution: in general, Bundle-Data contains Tor configuration and the default profile, so it should not be needed for Base Browser
  • Notice that the Linux startup script includes a reference to the default profile!
• We have a mac directory, but we rearrange it in code, and then delete the original one. We could just have the already prepared directory in the first place
• macOS still has the profiles.ini, but it isn't actually shipped (it's dropped in the above passage). We should remove it also form the repository for clarity.
• In the code we create an override.ini, used to disable the profile migration
  • Following in tor-browser#41577 (closed)
• macOS still has the files for the desktop dmg, let's remove them
• Base Browser will need different bundle data (I suggest we start differentiating the bundles already; we can copy the existing resources, for now, but we should create a new .DS_Store)
• macOS's .VolumeIcon.icns is still the old icon
  • See #28124 (closed) and tor-browser#41332 (closed)