Draft: Rename internal operation result definitions

Context

This is the fourth and final step to answer #2806 (closed).

Some types and functions are renamed in Apply_internal_results for consistency and clarity:

• TODO list changes here.

This merge request is rebased on !5149 (merged); only the top 0 commits are relevant 😆

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR