Unification of kgo updates in meto_run_kgo_script.sh

[Pierre-siddall]

In the meto_run_kgo_script.sh file the running of kgo updates on various different platforms uses several if statements which run similar checks on variables inside the script alongside outputting the same runtime messages to the user. These if statements can be refactored to be contained within one or two functions which will help speed up maintenance and improve the readability for developers in the future. This issue aims to address this by implementing a refactor of the kgo updates on each respective platform.