Refactor JIT support

JIT compilation was being done earlier than needed, but some
reorganization of the existing Gromacs is needed to move the
compilation to a place where call graphs and module dependencies flow
more smoothly.

Related, some code has moved from data_mgmt to generic nbnxn_gpu
files, because they were not really about data management.
The kernel type can't be decided in any other way, so dev_info needs to be passed, otherwise this causes a regression on CC 2.x.