Swaps path.Append from a single item method to accept a variadic list of string elements. Since 95% of all calls to path.Append were items, also adds a shorthand
AppendItem func to the interface for easy clarity. Finally, adds a Last() method to elements for getting the last element in the slice.
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#### Does this PR need a docs update or release note?
- [x] ⛔ No
#### Type of change
- [x] 🧹 Tech Debt/Cleanup
#### Test Plan
- [x] ⚡ Unit test
- [x] 💚 E2E