MHK wave-current superposition, added mass, inertia

[hkross]

This pull request is NOT ready to be merged

Feature or improvement description
This pull request allows for superposition of wave velocities and accelerations from SeaState with current velocities and accelerations from InflowWind for MHK turbines. MHK turbines can run with InflowWind alone if currents are considered without waves. If both currents and waves are modeled, SeaState is called by the glue code, and SeaState then calls InflowWind. Velocities and accelerations are summed in SeaState and passed out. New features also include the calculation of added mass loads due to structure motion and deformation as well as inertial loads from inflow turbulence.

Impacted areas of the software

• AeroDyn
• HydroDyn Morison
• SeaState
• OpenFAST glue code

Test results

• The OpenFAST fixed MHK r-test was unchanged. Since waves are not modeled for this case, SeaState was not called.
• Baselines for the OpenFAST floating MHK r-test were updated. Previously, the rotor inflow considered only currents from InflowWind and the structure inflow considered waves and currents from SeaState. Additionally, the current in SeaState was defined as constant (no shear) even though the current in InflowWind was defined with shear. The rotor and structure now see a consistent inflow with superimposed wave and current (with shear) velocities. To check the accuracy of the implementation, outputs from the MHK_AddedMass_Inertia branch were compared to outputs from existing r-test input files run on an upstream branch with equivalent waves and currents.
• All tests currently pass

To do - remaining code updates

• Update documentation
• Update api_change.rst
• Allow AeroDyn driver to call SeaState (wave-current superposition is currently not possible with the AeroDyn driver)
• Update all MHK r-tests with turbulent InflowWind files and coefficient values for added mass and inertia calculations
• Add new blade/tower added mass/inertia AeroDyn outputs

To do - pull request dependencies

• Merge dev-unstable-pointers into dev
• Merge Tight Coupling Solver #1850