Improve autocompletion latency

[MichaelRFairhurst]

I've noticed a big cause of latency is giant directive lists:

directives: [
  OMEGA_LIST_OF_ZILLIONS_OF_DIRECTIVES,
  ...
],
  template: "<one-directive-from-list>...

The cost of analyzing each directive's source to "link" them pre completion is really high.

It would be a really good idea to do this lazily.

Importance and severity are both really high because intelliJ (or maybe its the DAS plugin API, I forget) has a maximum timeout and for certain cases we miss that timeout entirely and autocompletion just doesn't even work.

[MichaelRFairhurst]

It seems @manuscle for instance is getting timeouts. Definitely a P1.