Today all these API calls have a sideeffect of making documents visible
to search requests. While this is sometimes desired it's an unnecessary sideeffect
and now that we have an internal (engine-private) index reader (#26972) we artificially
add a refresh call for bwc. This change removes this sideeffect in 7.0.
We use `:` for cross-cluster search (eg `cluster:index`), therefore, we should
not allow the ambiguity when allowing cluster or index names.
Relates to #23892
