PF Test Set type in Diff

[VenelinMartinov]

For the following collection types:

• set attribute
• set nested attribute
• set nested block

and the following schema variations:

• Optional
• Required
• Optional + Computed
  • set in the program
  • set by the provider
• Nested Optional + Computed
  • set in the program
  • set by the provider
• Default
• Default from a plan modifier
• Nested Default
• Nested Default from a plan modifier

each of these with:

• RequiresReplace plan modifier
• Nested RequiresReplace plan modifier

we should test the following scenarios:

• empty unchanged
• non-empty unchanged
• added empty
• added non-empty
• removed empty
• removed non-empty
• changed non-empty
• element added front
• element added middle
• element added end
• element removed front
• element removed middle
• element removed end
• shuffled

For each of these we should also test the unordered version of the scenario, where the elements are in a different lexicographical order, since that matters for re-ordering during planning

Note that the PF does not accept duplicate elements in a set, so we should not test for that.