Slicot: algorithms for systems and control theory

The subroutine library SLICOT provides Fortran 77 implementations of
numerical algorithms for computations in systems and control theory. Based on
numerical linear algebra routines from BLAS and LAPACK libraries, SLICOT
provides methods for the design and analysis of control systems.

Closes #16059.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>