Service ids should be autocompleted for decorates

[stof]

<service id="foo" decorates="|">
</service>

should trigger the completion.

Btw, it would be great to support the inner service of the decoration to avoid marking it as invalid in arguments (named <id>.inner by default, but can be overwritten by decorates-inner-name) already supported

[stof]

btw, it would be even better if the autocompletion could priorize services implemented the same interface than the current service.

[Haehnchen]

priorize services also supported here now