Context aware completion should in some only offer sources from context aware source

[Deraen]

(ns foo
  (:import [java.time █]))

Only candidates from ::namespaces-and-classes source make sense in this context but e.g. ::ns-mappings offers loads of candidates which hide the interesting results.

[alexander-yakushev]

Unfortunately there is no source←→context interaction at this point, but I'm willing to have it. If you have an idea how to suppress other sources when one source matched the context, please submit a PR.