Add updateable dialog properties, optimize API calls when creating or updating mapped objects

[danubie]

Fixes

• New-IdoitObject accetps array of hashtables to allow several categories while creating
• add func ConvertTo-IdoitObjectCategory
• add (private) function Get-IdoitMappedObjectChange
• fix (Mapping of dialog-fields could be better #45 ) update (set) of dialog properties

Minor

• Reduce API calls when creating or updating a mapped object
• Add -AllowDuplicates to be able to create objects with name that already exists
• Better content check of config yaml
• Enhance test cases