Refactor circuit library to not subclass QuantumCircuit

[mtreinish]

What should we add?

For qiskit 2.0 it would be good to refactor the circuit library to be a collection of circuit construction functions rather than QuantumCircuit subclasses. At the end of the day the majority of the classes in the circuit library are just using the constructor to build a QuantumCircuit and returning themselves and not specializing the circuit class. Moving to a function that returns a QuantumCircuit object will remove a layer in the type hierarchy and also make it clearer that the classes are just circuits. It also will make rust implementations of these functions easier after #12205 merges.

The one exception are the BlueprintCircuit classes. These try to adjust the internals of the QuantumCircuit to make them dynamically build (or rebuild/reconstruct if the properties change) based on provided properties. However, this functionality is not necessary anymore and it adds a lot of complexity to the classes that use it.

• Add equivalent circuit construction functions for all the circuit classes and use them internally for __init__ (in non-BlueprintCircuit classes).
• Deprecate the circuit classes and point to the new functions
• Deprecate BlueprintCircuit
• In Qiskit 2.0 remove all the QuantumCircuit subclasses in the circuit library.