Added missing data accessor to propagator products.
Added new adjoint method for propagator object
Added test for propagator adjoint.
Used new propagator adjoint in meson correlator calculation in TwoPoint.
Moved class constructor docstrings to class docstrings.
Moved WilsonLoops docstrings to google format.
Change get_propagator to make verbosity compatible with simulation
Began converting Simulation docstrings to google style ones.
Changed optional arguments in docstring to follow convention.
Updated docstrings to google type in Simulation.