Add a "Project Wiki Notes" submodule?

Problem/Motivation

We had this in the past and I run into this topic from time to time:

When administering Drupal pages, there are something special things you should be able to write down with the current page (URL / path) as context.
The context is not always an entity, so it doesn't belong there. It's always a path and sometimes a route, so it might be best and most flexible to do this on a per-path basis.

For example when administering the quite complex search_api project and a certain field shoud (not) be added to the index or something differs from our typical configuration, it would be great to have a note for that in the admin area on that page, which shows up if a note was added.

In the past we solved this using stickynotes and stickynotes_bonus but that was too heavy-weight and never worked that well.

As we'd want a cental overview for these notes, this is highly related to project_wiki,

There should be permissions like "View all notes" and "View own notes" etc. - we should first discuss the concept and make an MVP plan then. One thing to discuss is, if this should use the wiki entities with a flag or better use its own custom entity types.

In the end I think a smart solution here would be really helpful and improve stability in daily Drupal administration.

I looked for similar contrib modules but couldn't find a good one and I think a lightweight custom implementation makes sense here. Presumably using a block for the form and listing on the admin page and a central view for the list in the Wiki area.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes