Refactor cabal-install solver config log output

[erikd]

Includes:

• Apply some of @grayjay and @mpickering comments
• Fix Solver "rejecting" message is too verbose #4251

This is the PR #9541 rebased and fixed to build.

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[ulysses4ever]

Any chance you could add examples of what the new output looks like? Say, in the PR description.

[grayjay]

I haven't had a chance to look at the code yet, but, if I remember correctly, #9541 was a followup to #9159. Would it make sense to first update and merge #9159?

[Bodigrim]

This is going to break on boot package names like base-4.14.0.0/installed-4.14.0.0.

[erikd]

Yep, need to fix that.

[erikd]

I haven't had a chance to look at the code yet, but, if I remember correctly, #9541 was a followup to #9159. Would it make sense to first update and merge #9159?

According to this comment this seems like a precursor to #9159 .