Take care deprecation of GroverOperator

[woodsp-ibm]

#237 updated algorithms for the move from BlueprintCircuit based library classes to functions which return equivalent circuits but unlike the BlueprintCircuit based classes these functions return plain QuantumCircuits and cannot be updated, e.g. for number of qubits, in the way BluepintCircuit based classes allowed.

GroverOperator class has similarly been deprecated for a function. The class had some specific fields that are use by Grover - see #76 which noted that in regards of a typing mismatch/assumption.

Ideally we can support GroverOperator until its removed but Grover, and Amplification Problem, ought really to switch to being able to use the function and maybe even default to it - though the default can be changed later if it will cause compatibility issues but in that case should emit some sort of warning to that effect that things will be change.