Slow startup due to looking for services

[Bananeweizen]

Describe the bug
The search for services implementing ELK extensions is slow and defers the startup of the application, because OSGi has to load bundles, to unpack jars and to scan the manifests and class files.

This happens unconditionally on every startup, even if functionality of ELK is not used later.

Expected behavior
Zero runtime consumed, if ELK is not actively used. The initialization of the services should happen on demand only (i.e. on first access to any services). For us this slows down tests notably and even triggers the UI freeze monitor sometimes.

Screenshots

ELK Version
0.9.3

Additional context
If some of the core developers agree, I would like to prepare a PR which moves the initialization from the bundle start to the access of the services.

[soerendomroes]

Hi, a PR would be very much appreciated.