Add ADR AppCat Framework 2.0

[zugao]

Summary

This PR adds ADRs 0044, 0045, 0046, 0047. It also describes how each problem is to be resolved from the point of view of Service Users, Service Maintainers, Service Operators and Framework Engineers.

Please run make preview to read the rendered doc, check the index page Framework 2.0 from the Framework section on the left panel.

Checklist

• Try to isolate changes into separate PRs (to build a better changelog).
• Categorize the PR by setting a good title and adding one of the labels:
  change, decision, requirement/quality, requirement/functional, dependency
  as they show up in the changelog
• Link this PR to related issues if applicable.

[Kidswiss]

My first pass of reading this.

We should probably review and discuss this thing in stages. It's too large otherwise.

[mikeshootzz]

First of all, great job with the ADR! I agree with the comments from @Kidswiss and added some minor nitpicks.

[tobru]

This ADR is impossible to review in the current overly huge size. Please put some time into composing it into subpages which are graspable and reviewable.
It's clear that an AI assistant helped to write the ADR, which is great, but not really made for human reading IMHO, way too verbose.
Can you put some time into making it shorter again? Otherwise no one will be able to read it, ADRs are for human consumption and should be readable in a normal amount of time.

[mikeshootzz]

I don't have anything to add apart from what was already said. Splitting into multiple ADRs is a lot more readable.

[mikeshootzz]

Briefly went over it again. We've got a good baseline here that we can amend in the future.

[Kidswiss]

Should be good to start.

[tobru]

Some smaller things to improve, other than that, I think it's good to continue with starting the implementation.