Configuration flag to always use :as when adding aliases for namespaced keywords

[cmf]

Requested by @metametadata in this comment:

We consistently use :as everywhere, not :as-alias. I'd like to keep such style. So there could be a setting in Cursive settings to switch to such behaviour on completion and quick fixing.

It's not only a question of style, it could actually be incorrect to use :as-alias for specs.
As an experiment, I've replaced all [foo.specs :as specs] with [foo.specs :as-alias specs] in one project and now the compilation fails with Unable to resolve spec: :foo.specs/bar. Apparently at some point this spec is expected to be already registered, but due to :as-alias the ns foo.specs is actually never loaded.