Add a documentation class instead of a formatted string.

CMDHELPER-2915 - Reported by ACzChef

Right now functions have to pass in a string for their docs, that then later gets parsed into usable data.
My suggestion is to have a documentation class where you just define all the fields such as description, return type, arguments, name, etc. and use that instead. It would be cleaner, and less error prone.

No files or tests are named. Start by tracing where function documentation strings are defined, parsed, and consumed; identify the fields currently encoded in the format. Done means documentation is represented by a class with fields such as description, return type, arguments, and name, with all existing consumers updated and covered by the project's relevant tests.

Written by the indexing model from the issue text.