feat: absence proof v1

[iammadab]

Issue being fixed or feature implemented

Add verification function to generate absence result alongside the result set.
Works for only a subset of path queries, and will have to be upgraded (v2) to work for all possible path queries.

What was done?

• Added a new verification method for this feature
• Check terminal keys constraints
• Generate terminal keys
• Build a new result set from a combination of terminal keys and the old result set

How Has This Been Tested?

Unit tests (for the simple case)

Breaking Changes

Nope (additive)

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone