Change canonical form of single value integer range likes

[maximilianruesch]

Provides better support for integer range likes with matching upper and lower bounds by converting them to a concrete TheIntegerValue as their canonical form.

[!NOTE] We might want to implement this in more domain parts than the IntegerRangeValues, e.g. IntegerSetValues containing only one value. Any thoughts on this?

• Related to (and discovered during) #1

[maximilianruesch]

/it:test

[errt]

I agree that we should do something about this and we should make sure it is similar in all relevant domains. I'm not sure this is the right thing or place to do it, though. There's also DefaultIntegerRangeValues and its inner class IntegerRange which can model a full range, not just a single-element one. Then, there's also the constantValue method that is implemented in IntegerSetValues.IntegerSetLike, but not in IntegerRangeValues.IntegerRangeLike. I think we should look into these before settling on a solution.

[maximilianruesch]

/it:test