Add support for using Expr values in the control-flow builder interface

[jakelishman]

What should we add?

While #10224 is satisfied by opening up the typing of the manual-construction forms of the relevant control-flow operations, this is not the preferred manner for users to construct these.

The control-flow builder interface (with qc.if_test(...), etc) should have support for the condition or target as appropriate being an Expr value. This involves modifying the internal trackers and classical-resource resolvers in QuantumCircuit and the builder blocks to understand how to visit Expr types to find all used resources within them.

Depends on #10224.