[UPLC] [Test] Add scoping tests

[effectfully]

This adds scoping tests for UPLC the same way we have them for PIR. It also tweaks the way the scoping machinery handles case-expressions for PIR.

I didn't stumble upon any unexpected behavior.

[zliu41]

This looks good but we have a Pass data type (though currently only for PIR) where a Pass is associated with pre- and post-conditions. Would it be better to express the scoping properties in Pass instead of using this more ad-hoc way of testing?

[effectfully]

This looks good but we have a Pass data type (though currently only for PIR) where a Pass is associated with pre- and post-conditions. Would it be better to express the scoping properties in Pass instead of using this more ad-hoc way of testing?

The scoping tests are already rather complex, I'd rather not add any more complexity unless it's needed for something. Currently we only distinguish between

• transformations that require renaming and those that don't
• transformations that remove bindings and those that don't

I don't feel like adding an abstraction on top of this will make anything simpler or more readable. Particularly given that the handling logic is deep within the scoping tests machinery, so abstracting it out of there won't be nice.