Improved dependency application in exported HCL

[gerrytan]

This PR improves dependency application in the exported HCL by refactoring the deduplication logic and respecting transitive dependency when selecting implicit / depends_on strategy.

Given the below dependency graph:

flowchart LR
  A --"rg_name"--> R["Res. group"]
  B --"a_id"--> A
  B --"rg_name"-->R

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The exported HCL of A will have a depends_on to the resource group as per current behaviour, but B now only have implicit azurerm_a_resource.res-1.id TF address reference. The logic now understands that the transitive dependency to the Res. group is implied.