This moves all the things and rules logic away from NymeaCore
into their respective modules where it belongs.
One major change is the removal of the removePolicy functionality.
This was somewhat broken as it was only working for rules but not
for all the other modules like scripts, experiences etc. After
an attempt to create something that works with all modules it
really seemed that this does not make a lot of sence after all,
given that updating rules would in most cases leave something
very broken behind and removing them was the only sane thing to do.
On the other hand, experience plugins may not work well with such
a policy eithre as they may require to do their own special thing.
So in the end the removePolicy was dropped altogether. Apps should
instead figure out themselves what removal of a thing may imply and
inform the user about that beforehand.
