Restructure Puppet repository

In wiki-replica@467aa42c I proposed the steps below to improve the organization of modules in tor-puppet.git in such a way that we have a clearer partition between 3rd party modules, role/profile modules and "legacy" modules which are not yet converted to a role/profile.

The steps are:

• rename hiera/ to data/
• add site/ and legacy/ to modulepaths environment config
• move modules/profile/ and modules/role/ modules into site/
• move remaining modules in modules/ into legacy/

Once that's done and modules/ is empty, we can move on and work on switch from librarian to g10k (#41974 - closed)