Add symbolic support to Bloqs that expect control values as `cvs: Tuple[int, ...]`

[tanujkhattar]

Many bloqs (like MultiAnd, MultiControlPauli etc.) currently expect a control values object as a Tuple[int, ...]. This has a consequence that we cannot instantiate these objects symbolically.

We should replace cvs: Tuple[int, ...] with CtrlSpec object that can be instantiated symbolically as well.

[mpharrigan]

Would we want some sort of CtrlSpec that takes a parameter n for the number of controls and doesn't fully specify what the control values actually are? Usually during costing the difference between a positive and negative control is negligible

[tanujkhattar]

Yes, that's the idea.

[mpharrigan]

xref #716

sounds useful to me

[mpharrigan]

The newly-added Shaped symbolic utility #867 would be good here

[mpharrigan]

Is there a list of high priority bloqs that need this