Move tailslib to main repo

Feature Branch: feature/16935-move-tailslib-to-main-repo+force-all-tests, puppet-tails:feature/16935-move-tailslib-to-main-repo

Parent Task: #7036

Original created by @segfault on 16935 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information