Role name in success message

After a user is given a role (either sitewide or on a project), a success message is shown that mentions the role name. For example:

> Success! “Bob” has been given a Role of “Project Manager” on this Project.

This works well in English, but the role name ends up being incorrectly capitalized in French and Spanish. That's because we translate each role name only once: role names are used across components, so each role's corresponding message is defined in [`/src/locales/en.json`](/src/locales/en.json). In French, "Project Manager" is "Gestionnaire de projet", so the success message becomes:

> Succès ! "Bob" a reçu un rôle de "Gestionnaire de projet" dans ce projet.

However, "Gestionnaire de projet" should be lower case here.

I think we have a few options:

- Remove the role name from the success message. We could show "Success! “Bob” has been given a Role on this Project." without mentioning the role name.
- Make the role name lower case everywhere in French and Spanish. "Project Manager" is only translated once, so it could be translated in French as "gestionnaire de projet". It would be lower case in the dropdown.
- Translate the dropdown separately from the success message, translating each role twice.

I think I lean toward the first option, as that option seems simplest.