(core): remove ConfigurationElement
Description
This removes ConfigurationElement entirely from Sight, and forever...
It was a bit tough to remove it only from the AppConfig without touching the runtime, thus I cleaned everything at once.
This is a breaking change since the ConfigurationElement
class is removed, but this should not affect anybody since it was only used in the core system.
Closes #965 (closed) #959 (closed)
How to test it?
- Some manual testing of common applications should not hurt.