Feature/bmauer/fixes #1665

[bena-nasa]

Fixes #1665

Turns out the logic to check for duplicates was flawed. Really we only need to check a collection for duplicate aliases.
Either the user explicitly specified a duplicate alias OR they used two shortnames that are the same and provided no alias for one or both of them (in that case the alias is the shortname). I've modified the code to only check for duplicate alias. Now if there is a duplicate alias however it occurs I report a more descriptive message like this including the collection name for example:

pe=00005 FAIL at line=03333    MAPL_HistoryGridComp.F90                 <Caught collection geosgcm_prog with this duplicate alias or shortname if no alias provided: T2M>

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Trivial change (affects only documentation or cleanup)

Checklist:

• I have tested this change with a run of GEOSgcm (if non-trivial)
• I have added one of the required labels (0 diff, 0 diff trivial, 0 diff structural, non 0-diff)
• I have updated the CHANGELOG.md accordingly following the style of Keep a Changelog