Refactor BL use GH Copliot to remove the j index

### Are there any linked Issues or Pull Requests?

Umbrella #106
PR: #742

### Brief description

As requested by Chris, use an LLM Gen AI to refactor the boundary layer and remove the j index from the files.

Hand coded optimisations have already occurred to move the OMP and remove the j loops, therefore we can focus to just removing bounds in:
* The declarations
* The array bounds
* The calls in and out of the files.

As a psyclone script is already doing this for any files affected by the local PSyclone script, I'm focusing on scripts which PSyclone is not yet tackling (but may do in follow up work in #106)

### Further details of the issue.

_No response_