brew-linkapps creates symlinks again

Revert "Prevent linkapps from creating duplicate aliases"
Revert "linkapp: create Finder aliases"

This reverts commit e1a68f1ffbac9dc8209cc9ac2c8f2e34d11867af.
This reverts commit bf2e6023d1bac08739b4562e19e07db448f0aba3.

Closes #15308.