Update qcor demo examples

# QCOR - XACC IR Demo

QCOR IDE set-up: https://aide-qc.github.io/deploy/getting_started/

## Launch QCOR IDE: 

```

aide-qc --start

```

## Access:

```

http://CADES-IP:8080

```

## IDE Docker set-up

- Add `.ibm_config` and `.ionq_config`

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/// qaoa_placement.cpp: Topology placement example

/// Using the default placement:

/// qcor -qpu aer:ibmq_paris  qaoa_placement.cpp -print-final-submission

/// qcor -qpu aer:ibmq_guadalupe  qaoa_placement.cpp -print-final-submission

/// Change the placement:

/// qcor -qpu aer:ibmq_paris -placement enfield qaoa_placement.cpp -print-final-submission

/// qcor -qpu aer:ibmq_guadalupe -placement enfield qaoa_placement.cpp -print-final-submission

/// Can add -opt 1 to further combine single-qubit gates (mixer terms).

__qpu__ void qaoa_maxcut(qreg q, std::vector<double> gamma,

                  std::vector<double> beta,

- Circuit with an Identity sequence: repeating CNOT gates (no optimization), examining the expectation calculation (theoretical = 1.0) with and without noise mitigation. CLI option to enable noise mitigation on any backend (simulator and IBM)

- Sweeping VQE ansatz: showing the energy values with and without noise mitigation.

- [Skipped] Sweeping VQE ansatz: showing the energy values with and without noise mitigation.

## Notes:

/// Execute: 

/// ./a.out

// To show XACC IR execution (FTQC): add -print-final-submission option

// Iterative Quantum Phase Estimation:

// Only use 2 qubits to achieve 4-bit accuracy (normally require 5 qubits)

// The oracle is a -5*pi/8 pHase rotation;

// The oracle is a -5*pi/8 phase rotation;

__qpu__ void oracle(qubit q) {

  auto angle = -5.0 * M_PI / 8.0;

  U1(q, angle);