Replace qcompile with SerialCompiler in tests and documentation

qcompile is deprecated and all references to qcompile in the tests and documentation should be replaced by something based on SerialCompiler. Similar to what is done in !516 (merged).

Code snippet to help out future developers assigned to this task:

quantum_device = QuantumDevice()
quantum_device.hardware_config(hardware_cfg)

# setup qubits and stuff
...

compiler = SerialCompiler(name="compiler")
compiled_sched = compiler.compile(
    schedule=schedule, config=quantum_device.generate_compilation_config()
)