Wisdem

Many backend improvements and bug fixes in this release:

- Multiple fixes to the `compare_designs` routine following the enhancements to the composite layer optimization capability in the prior release
- Fix some typos in the user-defined constraints introduced in the prior release
- Ability to use the nice DifferentialEvolution heuristic optimization driver in OpenMDAO
- Alignment with the latest OpenMDAO release
- Switch to a python-based PreComp, instead of the compiled Fortran version to fix some of the Windows compilation struggles
- Fix and old bug on the rotation of the airfoil sections sent to PreComp for analysis
- Lots of small syntax changes to address deprecation warnings in third-party libraries
- Fix bug in calculation of bedplate mass for direct-drive downwind configurations
- Fix multiple bugs in the DNVGL structural code checks, especially for longitudinal stiffeners
- Capability for thrust-constrained design optimization

The PR brings in several changes:
Blade structure can be parametrized in the thickness of each layer, not only spar caps and reinforcements
There are new blade constraints to support inverse design studies (desired blade mass, desired natural frequencies)
New example and documentation to support inverse design
Update of installation steps (mamba)
Turbine gearbox can be desired with a desired torque density
User specified DVs, figure of merit, and constraints in support of WEIS Phase II
Strengthening of the sub-optimization to determine pitch angle across wind speeds in rotor_power.py
Cd0 no longer hard coded to 0
The list probably goes on

Highlights include:

- Better ability to adjust thickness as a design variable
- Changes to support the new IEA Wind 22-MW Reference Wind Turbine
- Better handling of multiple airfoil polars in the yaml-input file
- Remove duplicate code and capability between CCBlade and AirfoilPrep (AirfoilPrep has been fully removed)
- Fix bug in blade cross-sectional area calculation. Instead of doing this in PreComp, it is now done as a layup summation.
- Fix bug in sizing of main bearings for select drivetrain configurations

The next development tasks will involve more significant refactoring of the code to allow user-definitions of optimization problems and component mass / cost / stiffness values!