Remove assumptions about config file location

[markpayneatwork]

Is your feature request related to a problem? Please describe. At the moment KAPy.getConfig() loads the config file from an assumed location. This is not ideal and not particularly transparent, particularly when using KAPy inside other projects

Describe the solution you'd like

• Use the configfile: argument in Snakemake to set the configuration file. This will load the YAML into memory.
• Convert getConfig() to validateConfig() or similar, which focuses on doing the validation steps. This may or may not need to be completemented with an expandConfig() or augmentConfig(), which takes care of importing the sheets as well
• Consider creating a helper function loadConfig(), for use mainly in debuggin
• TinoPai and KADK should then pass their config into KAPy when importing the rules

[markpayneatwork]

Tested with TinoPai - looks like its working well. Closing