Stencil support for i-first kernels in PSyclone

[mo-alistairp]

PSyclone doesn't currently have support for i-first kernels. This means there is a need for the PSyKAl-lite subroutine invoke_jules_exp_kernel_type in LFRic apps science/um_physics_interface/source/psy/psykal_lite_phys_mod, which is called by science/um_physics_interface/source/algorithm/bl_exp_alg_mod.x90.

The corresponding PSyclone issue for this is #1948. I'll note down a relevant LFRic ticket - LFRic #3205.