Add additional checks with warning/error messages for turbomachinery cases.

[bigfooted]

Is your feature request related to a problem? Please describe.

In a discussion on cfd-online we concluded that some warning/error messages will be helpful to guide users in setting up turbomachinery cases.

https://www.cfd-online.com/Forums/su2/258309-su2-compressor-turbomachinery-case.html

Conclusion: Warning/error messages for the 3 points below will be very useful:

1) Rotation axis must be positive z-axis using right hand rule 2) Flow must be in positive z-direction 3) periodic faces cant be split i.e. you must have only x1 pair of periodic faces per blade row

[joshkellyjak]

I think a refactor of the turbovertex structure would be very beneficial in the long run and will address points 1 & 2, maybe this would be better from a user perspective rather than error messgaes. If we're going to add something that determines the relative orientation of the boundaries, we might as well make it so the geometric preprocessing can use this information to build the turbovertex structure for machines with arbitary inflow/outflow orientation. Currently mixed-flow machines are not possible in develop, we could allow these types of machine with this. We will also probably slim down the code quite significantly and bring large section up to date with C++ 11 standards.