- editing pages no longer needs the permission of viewing the history
- viewing past edits now is its own permission, still depending on
viewing the page itself
Effectively we only want to allow disabling the internal wiki
for now, but we'll have to answer certain usability questions
on what happens when a provider is deleted/disabled anyways, so
we'll make it technically possible to disable any provider, even
if we might not offer it for all of them out of the box.
The most likely starting scenario to have no wikis tab is that
the internal wikis are disabled and no external wiki is configured.
Includes all relevant entities we want to support in the beginning,
but does not yet include services and code designed to expose those
entities in any way.