Add circuit diagrams to source code (Qiskit#7350)

* Add circuit diagrams to test_hoare_opt.py

* Add circuit diagram to equivalence_library.py

* Add a TODO in equivalence_library.py

* Add circuit diagram to echo_rzx_weyl_decomposition

* Add circuit diagram to merge_adjacent_barriers.py

* Add circuit diagram to test/python/circuit/library

* Add circuit diagram to test/python/circuit

* Add circuit diagram to test/python/compiler

* Add circuit diagram to test/python/dagcircuit

* Add circuit diagram to test/python

* Format source code with black

* Chang block comment from string to line annotation

* Add circuit diagram to standard_gates

* Add parsed-literal before circuit diagram

* fix a lint problem

* Update circuit diagram in test

* Fix a lint problem

* Add blank lines before and after parsed-literal

Co-authored-by: Luciano Bello <bel@zurich.ibm.com>

qiskit/algorithms/amplitude_estimators/estimation_problem.py

@@ -221,7 +221,7 @@ def _rescale_amplitudes(circuit: QuantumCircuit, scaling_factor: float) -> Quant
 
     For example, for a scaling factor of 0.25 this turns this circuit
 
-    .. code-block::
+    .. parsed-literal::
 
                       ┌───┐
         state_0: ─────┤ H ├─────────■────
@@ -231,7 +231,7 @@ def _rescale_amplitudes(circuit: QuantumCircuit, scaling_factor: float) -> Quant
 
     into
 
-    .. code-block::
+    .. parsed-literal::
 
                       ┌───┐
         state_0: ─────┤ H ├─────────■────

test/python/algorithms/test_skip_qobj_validation.py

@@ -40,6 +40,13 @@ def setUp(self):
         super().setUp()
         self.random_seed = 10598
 
+        #       ┌───┐      ░ ┌─┐ ░
+        # q0_0: ┤ H ├──■───░─┤M├─░────
+        #       └───┘┌─┴─┐ ░ └╥┘ ░ ┌─┐
+        # q0_1: ─────┤ X ├─░──╫──░─┤M├
+        #            └───┘ ░  ║  ░ └╥┘
+        # c0: 2/══════════════╩═════╩═
+        #                     0     1
         qr = QuantumRegister(2)
         cr = ClassicalRegister(2)
         qc = QuantumCircuit(qr, cr)