[BUG] Changing controller instance type doesn't cause cluster to be update

[cartalla]

Describe the bug
I changed /slurm/SlurmCtl/instance_type and updated the config stack and CDK doesn't detect any stack changes.

[cartalla]

This is because the config file is now a jinja template that is stored in s3 and a custom resource expands the template and store the resolved template in s3. So the stack now doesn't see the parallel cluster config as an input to anything, just the path to the s3 object.

Update the custom resource to output the hash of config file and put that as an input the the parallelcluster custom resource.