Migrate `example_package()` to Data Package v2

[peterdesmet]

• Set the parameter `version = "2.0" as default
• Remove explicit version = "2.0" from tests
• Add explicit version = "1.0" in tests where Data Package v1 is required
• Remove explicit version = "2.0" in all examples
• If changes were implemented
  • Update documentation
  • Update examples (switch order)
  • Update NEWS.md
• Update support table in Migrate all functions to Data Package v2 #320