Create /opt directory everywhere

Summary:
[ Duplication of the Salt state ID /opt ]

When applying salt 'ysul' state.apply roles/devserver, an error was identified: the Salt state ID /opt was defined twice, in:

• roles/devserver/userland-software/init.sls
• roles/shellserver/userland-software/base.sls

Since /opt is a common system directory, the clean fix is to define it only once in roles/core/userland-software/init.sls, and
remove the duplication on /devserver and /shellserver.

Ref T2315

Reviewers: dereckson, Duranzed

Reviewed By: dereckson

Subscribers: Duranzed, dereckson

Maniphest Tasks: T2315

Differential Revision: https://devcentral.nasqueron.org/D4089