Add decompose instructions, when qiskit circuit is build.

[MHagelueken]

transpile() with keyword optimization_level >1 can delete gates with parameters that are redundant which leads to the code not being able to map parameters of original circuit onto transpiled circuit.

closes #306

[MoritzWillmann]

Thank you @MHagelueken for the quick fix. I have a couple of comments before we can merge this PR. Also can you please make sure the code formatting (black) checks go through 😄
Cheers Moritz

[David-Kreplin]

Do we need a decomposition in encoding_circuit.transpiled_encodig_circuit.py:

if "optimization_level" not in kwargs:
    kwargs["optimization_level"] = 3
if "seed_transpiler" not in kwargs:
    kwargs["seed_transpiler"] = 0
self._transpiled_circuit = transpile(self._circuit, self._backend, **kwargs)