fix(terraform_plan): compute the longest common prefix between two optional vertex

[lirshindalman]

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Description

Fixed a bug where the link between resources was incorrect when multiple nested modules were involved.
Updated the function to compute the longest common prefix between two module names by comparing all dot-separated parts instead of only the first two segments.

Fixes # (issue)
link between resources was incorrect when multiple nested modules were involved

New/Edited policies (Delete if not relevant)

Description

Include a description of what makes it a violation and any relevant external links.

Fix

How does someone fix the issue in code and/or in runtime?

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes

[maxamel]

Is it possible to add a test for the handled use-case ?