Add error messaging logging for ams jobs SO107 SCMSUITE-8725

[dormrod]

Description

Log any results of AMSJob.get_errormsg to the default logger at the end of the job.
This makes it clear in the std output what may have gone wrong e.g.

[05.12|13:56:39] Error message for job water_optimization was:
	 LICENSE INVALID
	 ---------------
	
	 Your license does not include module AMS version 2024.206 on this machine.
	
	 Module AMS
	 Version 2024.206
	 Machine: XXXXX
	
	 License file: ./license.txt

Add a small tweak to get_errormsg to handle license issues, and small unit test.

Note that this limits any error logs to 20 lines (arbitrary choice).

Also make the message

WARNING: Trying to obtain results of crashed or failed job crashing_job

slightly less spammy by ignoring it when called from ok, check or get_errormsg

[dormrod]