Define GUI patterns for (non-periodic) timing constraints
Currently, timing constraints get automatically generated from the timing specification.
It should be provided a user interface in the constraint modeling section, where "patterns" are given for specifying which subset of constraints shall be considered in a specific DSE run.
This is similar to what happens for HW property patterns.
We note that this does not apply to periodic constraints, which cannot be deselected and should be considered implicit. Running a schedule synthesis should actually not be allowed in the case when periods are not defined.