lapack/lapacke: change BLAS-related types to byte

Created by: vladimir-ch

In #38 we changed LAPACK-related types to byte because

• the code generation cannot decide to what type it is should map a comp or job parameter based solely on its name and any other scheme is not practical
• lapacke is a very low-level package and we don't have to or even should not provide any support in form of types and constants from the lapack package.

I think we should do the same for BLAS-related types and constants like blas.Side, blas.Transpose, blas.Uplo. The first point does not apply here but the second point is strong enough to justify the change of these types to byte.