* Update the naming convention for collective APIs to ensure consistency across the interface.
* Move all collective API declarations to rocshmem_COLL.hpp
* The following APIs were updated as part of this change:
- `barrier`
- `barrier_all`
- `sync`
- `sync_all`
- `all_to_all`
- `broadcast`
- `fcollect`
- `all_reduce`
* Update header file generation code for collective APIs
add the interfaces required to support rocshmem initialization
through the uniqueID mechanism. At the moment this still maps to
MPI initialization underneath the hood, but adding the functions might
simplify the porting of some applications to rocshmem. In addition, if
we need to transition away from MPI one day, this is also one step into
this direction.