Improve cluster support/integration

[TBradley27]

At the moment, the application can very easily be ran on standard HPC architectures using standard HPC job schedulers (e.g. slurm/LSF). However, in the current implementation, the whole pipeline is ran as one job, with a single set of core requirements, and a single set of memory requirements for each rule.

However, Snakemake allows developers to implement HPC resource management and submission on a rule-by-rule basis. Taking advantage of this feature will reduce the overall cost of FilTar HPC submissions, likely reduce HPC queue waiting times, and probably improve pipeline logging/administration easier as well