Role for Translators which doesn't require full admin rights

Is your feature request related to a problem? Please describe.
As a multinational community, we want to enable our community to translate the user generated content (meetings, blogs, content etc) on our Decidim instance. Presently the only way to do this is add them as a full admin, which means they have access to areas of Decidim which are sensitive and they would not normally have access to.

Describe the solution you'd like
I'd like for there to be a role type which is specifically for translations, or even better to have this available to anyone with a review process, which doesn't give any elevated administrative permissions that a normal user would have. This role (if a role were used) could be assigned to a user in addition to whatever access they already have, permitting them to translate content they have access to. Ideally they should not be able to edit the base content, just add a translation. It could be restricted to a specific language when the role is assigned, or be open to all languages, perhaps.

Describe alternatives you've considered
At present we add all users as administrators and explain they have special privileges which we trust them to respect. It's not ideal, especially if we have things like elections happening where they can see the votes in progress.

Additional context
This works really nicely with our Knowledgebase system, PHPKB, where any user can translate any user-generated content if they have a 'writer' role applied which is needed to create content, but we have to elevate to admin users to allow people to translate the user interface (which requires admin access).

Does this issue could impact on users private data?
Currently it does, because translators have access to data they should not need to access.

Funded by
I don't have funding available, proposing this as I think it will become a larger issue the more multilingual communities you have using Decidim.