Resolve ee-specific-line differences in environment_item.vue

gitlab-org/gitlab-ee!6672 introduces some lines to app/assets/javascripts/environments/components/environment_item.vue which are not in CE and we need to decide on the best action to harmonize these versions of the component.

There are three primary options:

1. Leave these differences as-is as ~"technical debt" until a better solution for extending .vue component templates is forthcoming (there are dozens of other such inconsistencies among other .vue files currently)

2. Port the changes back to CE. Essentially this will introduce code into CE that will never be utilized (the code just produces a "protected" badge next to an environment name when an object property is true)

3. Create a copy of the environment_item.vue with the changes which will be used only in EE. This would introduce a lot of duplicate code and could be error prone and difficult to maintain.

/cc @timzallmann