fixes #15416 - update untouched templates during seed

During upgrades, we run db:seeds again, but provisioning templates
are never updated again after the first time. This causes issues
like when those templates cease working with the newer versions of
Foreman. So, this PR updates the contents of the templates if a...

Fixes #14783 - Limit OS description to 255

This field forms part of 'os.title' too.

Fixes #15276 - view permissions start with view

fixes #14664 - support IPv6 in Nic, Hosts and Hostgroups models

Fixes #15213 - handle host update when proxy is unreachable

Fixes #14546 - ability to restrict *_external_variables
Fixes #14535 - corrects permissions for smart class parameters

Fixes #15038 - reset User cache during migration

This commit will update the cache information about columns
on the User table. This is needed due to errors observed during
certain upgrades involving the Katello plugin.

Refs #3809 - Turning on some rubocop cops

fixes #13437 - Bookmarks public attribute set to required

fixes #14661 - support IPv6 subnets