Added VERSION and SOVERSION to KOKKOS_INTERNAL_ADD_LIBRARY

[jrmadsen]

The question here is whether we want the SOVERSION to be ${Kokkos_VERSION_MAJOR} or ${Kokkos_VERSION_MAJOR}.${Kokkos_VERSION_MINOR}. The answer probably boils down to whether we want to "guarantee" new minor versions don't introduce new symbols which must be directly linked to. Given all the templates, I went ahead and assumed that would be difficult to enforce so I set SOVERSION to use the major and minor version (but we can change this).

Previously, we had:

libkokkoscore.3.3.0.so
libkokkoscore.so -> libkokkoscore.3.3.0.so

This produces:

libkokkoscore.3.3.0.so
libkokkoscore.3.3.so -> libkokkoscore.3.3.0.so
libkokkoscore.so -> libkokkoscore.3.3.so

Closes #3687