Help Tab Order should be based on the Priority Argument

[34370] made the order that tabs are returned respect the order they are added, however it broke the respect of priority. By using a ksort instead of a sort, we can restore that default behavior. This adjusts the unit tests so that both order added and priority are tested.

Props meitar,  swissspidy, jorbin
Fixes #35215. See #33941.

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