Refactor GATK4 tool IDS

[illusional]

Currently, it's up to each GATK4 tool to declare it's own tool(self): -> str, it would be much better (way more consistent), if the Gatk4 tool base declared the ID as:

class Gatk4ToolBase(BioinformaticsTool, ABC):
    def tool(self) -> str:
        return "Gatk4" + self.gatk_command()
    # other tool definitions

Removing the other GATK def tool lines from the GATK tools is the time-consuming bit.