Connection discovery and IDE identifier resolving spec

[mwu-tow]

Pull Request Description

This PR describes language rules as I understand them in a scope necessary to implement proper connection discovery (#320). It covers general language rules (that are relevant) and assumptions and simplifications that IDE can currently make.

Also, a number of TODO notes are left for things that I don't understand yet or that haven't been clearly specified. They are not blocking the implementation for connections, rather something that we are allowed to fill out later.

Important Notes

Checklist

Please include the following checklist in your PR:

• [x] The documentation has been updated if necessary.
• [x] All code conforms to the Rust, Scala, Java or Haskell style guides as appropriate.
• [x] All code has been tested where possible.

[farmaazon]

@iamrecursion could you please look at this document again? It was written before removing UFCS and likely outdated in many places.

[wdanilo]

What is the status of this ?

[farmaazon]

What is the status of this ?

It waits for @iamrecursion after-UFCS-check. See my comment above. And because we have other priorities right now, it seem properly frozen in icebox.