error-stack: clarify documentation of HookContext

[indietyp]

🌟 What is the purpose of this PR?

#1693 separated fmt::HookContext into hook::HookContext and fmt::HookContext, so that it can be used in #1558. While working, the problem is that documentation doesn't render correctly because hook::HookContext is private in public. Therefore unreachable rustdoc is unable to navigate to the type, and the documentation is incomplete.

This PR moves to a macro-based approach to enable better documentation. Instead of using an unreachable public type, we have a macro that implements the necessary common functions. This is by far not ideal, but I found this to be the best way without compromising #1558 or future hooks.

[codecov]

Codecov Report

Merging #1987 (c8273d9) into main (bfb341a) will decrease coverage by 0.54%.
The diff coverage is 8.54%.

@@            Coverage Diff             @@
##             main    #1987      +/-   ##
==========================================
- Coverage   57.59%   57.06%   -0.54%     
==========================================
  Files         265      265              
  Lines       18940    19118     +178     
  Branches      421      421              
==========================================
  Hits        10909    10909              
- Misses       8026     8204     +178     
  Partials        5        5              

Flag	Coverage Δ
backend-integration-tests	3.66% <ø> (ø)
error-stack	82.54% <8.54%> (-8.50%)	⬇️
unit-tests	1.49% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
packages/libs/error-stack/src/lib.rs	38.46% <ø> (ø)
packages/libs/error-stack/src/fmt/hook.rs	44.30% <0.54%> (-53.66%)	⬇️
packages/libs/error-stack/src/hook/context.rs	78.89% <94.11%> (ø)

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[TimDiekmann]

Thanks, @indietyp, this is much better (and also does unbreak SemVer for this struct) 🎉

[indietyp]

I took the liberty of cleaning fmt::hook up and re-enabling dead_code and unused_imports.

[indietyp]

Sorry, @TimDiekmann, I need another review D: I just realized that I can remove all cfg guards in the hook.rs because it is only conditionally enabled anyway.

[TimDiekmann]

I think the last commit was a good idea 😄

[indietyp]

/trunk merge

[trunk-io]

🚫 This pull request has been removed from the merge queue (details).

[trunk-io]

😎 Merged successfully (details).