Clock scopes

Like defined in Ecdar/j-Ecdar#97, scoping clocks may also prove beneficial for `Reveaal` in a clock reduction aspect. This could help with active clock reduction (#157) and may provide an easier way of performing clock reduction on `SystemRecipe` (#155).

Start by reading Ecdar/j-Ecdar#97 and the related Reveaal issues #157 and #155. Investigate how clock reduction currently relates to SystemRecipe and determine the intended scope for clock scoping; done requires an agreed design and an implementation that demonstrates the proposed reduction benefit.

Written by the indexing model from the issue text.