Reformat loading of modules in suite-config files for easier editing

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

_No response_

### Brief description

When developing changes, I often want to modify the modules being loaded. The current syntax for loading modules is a bit annoying for this and it is much easier to edit a multiline string, eg.:

```jinja
# Current
{% set ex1a_compiler_gnu = 'module switch cpe/22.11 cpe/23.05 ; ' ~
'module load PrgEnv-gnu ; '~
'module load gcc/12.2.0 ; '~
'module load lfric-gnu/12.2.0/3.0+ || true' %}

# Suggested
{% set ex1a_compiler_gnu = '''
module switch cpe/22.11 cpe/23.05
module load PrgEnv-gnu
module load gcc/12.2.0
module load lfric-gnu/12.2.0/3.0+ || true
''' %}
```

### Further details of the issue.

_No response_