Refactor SortOrder & SortOrderConfiguration into one enum

[jzyrobert]

• Not an issue fix, but as part of a previous PR I noticed that a separate object SortOrderConfiguration and type SortOrder are used to emulate an enum.
• Also replaced 2 occurrences of direct string comparison with the enum equivalent.

[isidorn]

@jzyrobert thanks for this. Did you verify that this does not break anything and that the explorer.sortOrder still works as expected?
Can you please resolve conflicts with master and then we can look into merging this? Thanks

[jzyrobert]

@isidorn Works as before:

I have rebased and resolved the conflict.

[isidorn]

Thanks a lot for this. Merging in.