Copy required packages from `COSIMA/spack_packages`, rename root `access-om3` SBD

[CodeGat]

The current 0.x.0 spack.yaml from COSIMA requires spack packages that we do not have in our repository.
Currently, the ones that will have to be copied are:

• fms
• fortranxml

Furthermore, in the spack.yaml we are working with in ACCESS-NRI/ACCESS-OM3#5, we initially had our root SBD element as access-om3-virtual, with the access-om3 SPD being it's only dependency.
We are looking to rename the following packages, in order to keep the names that the user will interact with more simple:

• access-om3 (SPD) renamed to access-om3-cmake (open to change the name)
• access-om3-virtual (SBD) renamed to access-om3