Members see the workspace name in settings, and other fixes

Fixes

• Members who can’t rename the workspace now see its name under Settings > Workspace, with a note that renaming needs admin permission, instead of a “You don’t have access to this section” warning in place of the whole section.
• If someone else renames the workspace while you have Settings > Workspace open, your tab picks up the new name instead of offering to save the old one over it.
• A single sign-on link that names an identity provider Screenly doesn’t know now shows a page saying so, instead of an error page.