suzerain: #2492 add negative Blasius eta

Data generated from https://github.com/RhysU/blasius using 'blasius -2'.
Intent is to adjust the spline fits to provide better behavior at eta=0.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42258 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: #2492 prep to extend spline domain

This is sizeable refactor with some changes waiting in the
wings, but it should be a NOP from an externally observable
perspective.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42259 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: #2492 add points at infinity

Attempt to avoid ARIMA-related badness within the
points of interest at finite eta.

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42260 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: add blasius wall derivative test

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42261 0bd85f0b-c151-43b9-a1e9-27231104551f
suzerain: #2492 improve blasius fit at wall

git-svn-id: https://svn.ices.utexas.edu/repos/pecos/suzerain/trunk@42262 0bd85f0b-c151-43b9-a1e9-27231104551f